Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P80098 (monocyte chemoattractant protein)
 1,800 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The protein human CC chemokine ligand 2 (CCL2, also known as monocyte chemoattractant protein 1 or MCP-1) has been synthesized using a combination of solid phase peptide synthesis (SPPS) and native chemical ligation (NCL). The thioester-peptide segment was synthesized using the sulfonamide safety-catch linker and 9-fluorenylmethoxycarbonyl (Fmoc) SPPS, and pseudoproline dipeptides were used to facilitate the synthesis of both CCL2 fragments. After assembly of the full-length peptide chain by NCL, a glutathione redox buffer was used to fold and oxidize the CCL2 protein. Synthetic human CCL2 binds to and activates the CCR2 receptor on THP-1 cells, as expected. CCL2 was crystallized and the structure was determined by X-ray diffraction at 1.9-A resolution. The structure of the synthetic protein is very similar to that of a previously reported structure of recombinant human CCL2, although the crystal form is different. The functional CCL2 dimer for the crystal structure reported here is formed around a crystallographic twofold axis. The dimer interface involves residues Val9-Thr10-Cys11, which form an intersubunit antiparallel beta-sheet. Comparison of the CCL2 dimers in different crystal forms indicates a significant flexibility of the quaternary structure. To our knowledge, this is one of the first crystal structures of a protein prepared using the sulfonamide safety-catch linker and NCL.
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PMID:Synthesis by native chemical ligation and crystal structure of human CCL2. 2009 76

Our previous studies have demonstrated that hematopoietic stem cells (HSCs) are a novel source of carcinoma-associated fibroblasts. However, the mechanisms regulating recruitment and homing of HSC-derived carcinoma-associated fibroblasts or their precursors to the tumor microenvironment are unknown. Herein, we demonstrate using a single cell transplantation model that circulating fibroblast precursors (CFPs) are of HSC origin. This population increased with tumor burden in vivo and functional in vitro studies showed that CFPs preferentially migrated and differentiated into fibroblasts in response to tumor, suggesting that HSC-derived CFPs serve as an intermediate between the bone marrow and tumor. Based on this chemotactic ability and our demonstration of a monocyte lineage origin for CFPs, we investigated the role of monocyte chemoattractant protein (MCP1) in mediating CFP recruitment/homing. Blocking tumor-produced MCP1 inhibited in vitro migration of CFPs in response to multiple tumor types, indicating broad biological significance for this CFP/chemokine interaction. In vivo, CCR2-expressing CFPs increased in circulation during the period of active tumor growth and stromal development. Inhibition of MCP1 during tumor development resulted in decreased tumor volume in tumor-bearing mice. Together these findings confirm an HSC origin for CFPs, demonstrate a role for MCP1 in regulating their contribution to the tumor microenvironment, and suggest a potential therapeutic target for limiting tumor growth.
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PMID:MCP1 directs trafficking of hematopoietic stem cell-derived fibroblast precursors in solid tumor. 2016 69

The extracellular protease plasmin cleaves mouse MCP1 (monocyte chemoattractant protein 1) at lysine 104, releasing a 50-amino acid C-terminal domain. The cleavage event increases the chemotactic activity of MCP1 and, by doing so, promotes the progression of excitotoxic injury in the central nervous system in pathological settings. The mechanism through which the cleavage event enhances MCP1-mediated chemoattraction is unknown; to investigate it, we use wild-type and mutant forms of recombinant MCP1. Full-length MCP1 (FL-MCP1) is secreted by cells as a dimer or multimer. We show that a mutant truncated at the C terminus, K104Stop-MCP1, does not dimerize, revealing that the C terminus mediates the interaction. MCP1 interacts with the monocyte/microglia receptor CCR2. The interaction is critical to the function of MCP1 because CCR2(-/-) microglia do not undergo chemotaxis in response to MCP1 stimulation. We show that stimulation of microglia with FL-MCP1 or K104Stop-MCP1 triggers CCR2 internalization, whereas a mutant form unable to be cleaved at lysine 104 (K104A-MCP1) is relatively ineffective in this assay, suggesting that the C-terminal region interferes with the MCP1-CCR2 interaction. Moreover, FL-MCP1 and K104Stop-MCP1 stimulation leads to activation of Rac1, a small GTPase involved in cell migration. Conversely, MCP1-stimulated microglial migration is blocked by the Rac1 inhibitor, NSC23766, demonstrating the requirement for Rac1 effector pathways in this response. Taken together, we propose a model for MCP1 localization, activation, and function based on the initial presence and then removal of its C terminus, coupled with a requisite downstream signaling pathway from CCR2 stimulation to Rac1 activation.
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PMID:The C terminus of mouse monocyte chemoattractant protein 1 (MCP1) mediates MCP1 dimerization while blocking its chemotactic potency. 2068 71

Autoimmune diseases represent one of the most challenging clinical entities with unmet medical needs, so the continued development of novel therapeutics is well justified. Most autoimmune diseases are marked by the infiltration of lymphomyeloid cells in target tissues, leading to inflammation and tissue damage. This process is guided by chemokines that act as signaling bridges amidst a complex network of immune cells. For example, monocytes are believed to be the primary cell type responsible for pathology initiation and tissue damage, while T lymphocytes are thought to orchestrate the process by secreting more cytokines/chemokines to amplify leukocyte homing. Many studies have addressed the molecular basis of monocyte recruitment in different autoimmune diseases, and the conclusions pointed to a major role played by monocyte chemoattractant protein 1 (MCP-1), also known as CC chemokine ligand 2 (CCL2), and its cell-surface receptor, CC chemokine receptor (CCR) 2. These findings suggest that by interfering with CCL2 or its receptor, it is possible to inhibit the progression of CCR2-dependent diseases. Therefore, future therapy design targeting a maladapted immune response could target chemokine receptors starting with the CCL2-CCR2 axis.
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PMID:A CCL2-based fusokine as a novel biopharmaceutical for the treatment of CCR2-driven autoimmune diseases. 2108 26

Mouse CCL8 is a CC chemokine of the monocyte chemoattractant protein (MCP) family whose biological activity and receptor usage have remained elusive. Here we show that CCL8 is highly expressed in the skin, where it serves as an agonist for the chemokine receptor CCR8 but not for CCR2. This distinguishes CCL8 from all other MCP chemokines. CCL8 responsiveness defined a population of highly differentiated, CCR8-expressing inflammatory T helper type 2 (T(H)2) cells enriched for interleukin (IL)-5. Ccr8- and Ccl8-deficient mice had markedly less eosinophilic inflammation than wild-type or Ccr4-deficient mice in a model of chronic atopic dermatitis. Adoptive transfer studies established CCR8 as a key regulator of T(H)2 cell recruitment into allergen-inflamed skin. In humans, CCR8 expression also defined an IL-5-enriched T(H)2 cell subset. The CCL8-CCR8 chemokine axis is therefore a crucial regulator of T(H)2 cell homing that drives IL-5-mediated chronic allergic inflammation.
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PMID:Mouse CCL8, a CCR8 agonist, promotes atopic dermatitis by recruiting IL-5+ T(H)2 cells. 2124 98

Chemokines are small secreted proteins that play an important role in immune responses and have also been shown to be involved in cartilage development and contributing to pathogenesis of a variety of diseases. They present a conserved 3D structure, so-called IL8-like chemokine fold, which is supported by conserved cysteines forming intra-molecular disulfide bonds. These cysteine sequence motifs have often been used to find new chemokine family members by sequence-based database searches. However, it has been shown that different patterns can provide disulfide bonds fitting into an IL8-like architecture, which has been the key to identify new remote homologues of the IL8-like chemokine family. We report a structural-functional characterization of cytokine-like protein 1 (Cytl1) by a combination of different computational structure-based techniques. Previous studies based on sequence analysis and secondary structure predictions reported that Cytl1 might adopt a 4-helical cytokine fold. However, our detailed molecular modeling studies and structure-based functional analysis strongly suggest that Cytl1 is more likely to adopt an IL8-like chemokine fold, in particular similar to CCL2 (monocyte chemoattractant protein 1, MCP-1). Moreover, we identify in a CCL2-like 3D model of Cytl1 the necessary reported features to signal through the chemokine receptor CCR2. Those discovered structural features of Cytl1 as CCL2-like chemokine, together with the fact that both, CCL2 and Cytl1, are known to be involved in cartilage development and pathogenesis of osteoarthritis and rheumatoid arthritis, make us hypothesize that Cytl1 could be a structurally and functionally related analog of CCL2 signaling through the chemokine receptor CCR2.
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PMID:Identification of CCR2-binding features in Cytl1 by a CCL2-like chemokine model. 2132 34

Intestinal failure is common in patients with septic shock, with dysfunction of the gut often manifesting as both a cause and consequence of their critical illness. Most studies investigating the pathogenesis of intestinal failure focus on the systemic aspect, although few data examine the inflammatory signaling in the intestinal lumen. Having previously demonstrated apical/luminal chemokine secretion in an in vitro model of intestinal inflammation, we hypothesized that endotoxemia would induce secretion of proinflammatory chemokines into the intestinal lumen. In addition, we examined the contribution of these mediators to intestinal dysmotility. C57/BL6 male mice were injected intraperitoneally with LPS. Serum, intestinal tissue, and intestinal luminal contents were harvested for cytokine analysis. For intestinal motility studies, a transit assay was performed after oral gavage of chemokines. Caco-2 cells grown on Transwell culture inserts were used to examine the role of the intestinal epithelium in chemokine secretion. Monocyte chemoattractant protein 1 (MCP-1/CCL2) and macrophage-derived chemokine (MDC/CCL22) were secreted into the lumen of multiple segments of the gut during endotoxemia in mice. In vitro work showed that the intestinal epithelium participates in monocyte chemoattractant protein 1 and MDC secretion and expresses the CCR2 and CCR4 receptors for these chemokines. Intestinal transit studies show that oral gavage of MDC results in impaired gut motility. This study demonstrates that the intestinal lumen is an active compartment in the gut's inflammatory response. Proinflammatory chemokines are secreted into the intestinal lumen during endotoxemia. These intraluminal chemokines contribute to intestinal dysmotility, complicating intestinal failure.
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PMID:Proinflammatory chemokines in the intestinal lumen contribute to intestinal dysfunction during endotoxemia. 2208 1

CC chemokine ligand-2 (CCL2)/monocyte chemoattractant protein (MCP)-1 expression is upregulated during pulmonary inflammation, and the CCL2-CCR2 axis plays a critical role in leukocyte recruitment and promotion of host defense against infection. The role of CCL2 in mediating macrophage subpopulations in the pathobiology of noninfectious lung injury is unknown. The goal of this study was to examine the role of CCL2 in noninfectious acute lung injury. Our results show that lung-specific overexpression of CCL2 protected mice from bleomycin-induced lung injury, characterized by significantly reduced mortality, reduced neutrophil accumulation, and decreased accumulation of the inflammatory mediators IL-6, CXCL2 (macrophage inflammatory protein-2), and CXCL1 (keratinocyte-derived chemokine). There were dramatic increases in the recruitment of myosin heavy chain (MHC) II IA/IE(int)CD11c(int) cells, exudative macrophages, and dendritic cells in Ccl2 transgenic mouse lungs both at baseline and after bleomycin treatment compared with levels in wild-type mice. We further demonstrated that MHCII IA/IE(int)CD11c(int) cells engulfed apoptotic cells during acute lung injury. Our data suggested a previously undiscovered role for MHCII IA/IE(int)CD11c(int) cells in apoptotic cell clearance and inflammation resolution.
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PMID:A macrophage subpopulation recruited by CC chemokine ligand-2 clears apoptotic cells in noninfectious lung injury. 2228 13

Inflammatory cell infiltration in the liver is a hallmark of nonalcoholic steatohepatitis (NASH). The chemokine-chemokine receptor interaction induces inflammatory cell recruitment. CC-chemokine receptor (CCR)2 is expressed on hepatic macrophages and hepatic stellate cells. This study aims to investigate the therapeutic potential of CCR2 to NASH. Twenty-two weeks on a choline-deficient amino acid-defined (CDAA) diet induced steatosis, inflammatory cell infiltration, and liver fibrosis with increased CCR2 and monocyte chemoattractant protein (MCP)-1 expression in the wild-type livers. The infiltrated macrophages expressed CD68, CCR2, and a marker of bone marrow-derived monocytes, Ly6C. CCR2(-/-) mice had less steatosis, inflammatory cell infiltration, and fibrosis, and hepatic macrophages expressing CD68 and Ly6C were decreased. Toll-like receptor (TLR)4(-/-), TLR9(-/-), and MyD88(-/-) mice had reduced hepatic macrophage infiltration with decreased MCP-1 and CCR2 expression because TLR signaling is a potent inducer of MCP-1. To assess the role of Kupffer cells at the onset of NASH, Kupffer cells were depleted by liposomal clodronate. The Kupffer cell depletion ameliorated steatohepatitis with a decrease in the MCP-1 expression and recruitment of Ly6C-expressing macrophages at the onset of NASH. Finally, to test the therapeutic potential of targeting CCR2, a CCR2 inhibitor was administered to mice on a CDAA diet. The pharmaceutical inhibition of CCR2 prevented infiltration of the Ly6C-positive macrophages, resulting in an inhibition of liver inflammation and fibrosis. We concluded that CCR2 and Kupffer cells contribute to the progression of NASH by recruiting bone marrow-derived monocytes.
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PMID:Hepatic recruitment of macrophages promotes nonalcoholic steatohepatitis through CCR2. 2244 58

Osteoarthritis is one of the leading causes of chronic pain, but almost nothing is known about the mechanisms and molecules that mediate osteoarthritis-associated joint pain. Consequently, treatment options remain inadequate and joint replacement is often inevitable. Here, we use a surgical mouse model that captures the long-term progression of knee osteoarthritis to longitudinally assess pain-related behaviors and concomitant changes in the innervating dorsal root ganglia (DRG). We demonstrate that monocyte chemoattractant protein (MCP)-1 (CCL2) and its high-affinity receptor, chemokine (C-C motif) receptor 2 (CCR2), are central to the development of pain associated with knee osteoarthritis. After destabilization of the medial meniscus, mice developed early-onset secondary mechanical allodynia that was maintained for 16 wk. MCP-1 and CCR2 mRNA, protein, and signaling activity were temporarily up-regulated in the innervating DRG at 8 wk after surgery. This result correlated with the presentation of movement-provoked pain behaviors, which were maintained up to 16 wk. Mice that lack Ccr2 also developed mechanical allodynia, but this started to resolve from 8 wk onwards. Despite severe allodynia and structural knee joint damage equal to wild-type mice, Ccr2-null mice did not develop movement-provoked pain behaviors at 8 wk. In wild-type mice, macrophages infiltrated the DRG by 8 wk and this was maintained through 16 wk after surgery. In contrast, macrophage infiltration was not observed in Ccr2-null mice. These observations suggest a key role for the MCP-1/CCR2 pathway in establishing osteoarthritis pain.
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PMID:CCR2 chemokine receptor signaling mediates pain in experimental osteoarthritis. 2318 4


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