Macrophage inflammatory protein-1 alpha. A novel chemotactic cytokine for macrophages in rheumatoid arthritis

Lumbar instability remodels cartilage endplate to induce intervertebral disc degeneration by recruiting osteoclasts via Hippo-CCL3 signaling

Degenerated endplate appears with cheese-like morphology and sensory innervation, contributing to low back pain and subsequently inducing intervertebral disc degeneration in the aged population.1 However, the origin and development mechanism of the cheese-like morphology remain unclear. Here in this study, we report lumbar instability induced cartilage endplate remodeling is responsible for this pathological change. Transcriptome sequencing of the endplate chondrocytes under abnormal stress revealed that the Hippo signaling was key for this process. Activation of Hippo signaling or knockout of the key gene Yap1 in the cartilage endplate severed the cheese-like morphological change and disc degeneration after lumbar spine instability (LSI) surgery, while blocking the Hippo signaling reversed this process. Meanwhile, transcriptome sequencing data also showed osteoclast differentiation related gene set expression was up regulated in the endplate chondrocytes under abnormal mechanical stress, which was activated after the Hippo signaling. Among the discovered osteoclast differentiation gene set, CCL3 was found to be largely released from the chondrocytes under abnormal stress, which functioned to recruit and promote osteoclasts formation for cartilage endplate remodeling. Over-expression of Yap1 inhibited CCL3 transcription by blocking its promoter, which then reversed the endplate from remodeling to the cheese-like morphology. Finally, LSI-induced cartilage endplate remodeling was successfully rescued by local injection of an AAV5 wrapped Yap1 over-expression plasmid at the site. These findings suggest that the Hippo signaling induced osteoclast gene set activation in the cartilage endplate is a potential new target for the management of instability induced low back pain and lumbar degeneration.

Comprehensive analysis revealed the immunoinflammatory targets of rheumatoid arthritis based on intestinal flora, miRNA, transcription factors, and RNA-binding proteins databases, GSEA and GSVA pathway observations, and immunoinfiltration typing

OBJECTIVE

Rheumatoid arthritis (RA) is a chronic inflammatory arthritis. This study aimed to identify potential biomarkers and possible pathogenesis of RA using various bioinformatics analysis tools.

METHODS

The GMrepo database provided a visual representation of the analysis of intestinal flora. We selected the GSE55235 and GSE55457 datasets from the Gene Expression Omnibus database to identify differentially expressed genes (DEGs) separately. With the intersection of these DEGs with the target genes associated with RA found in the GeneCards database, we obtained the DEGs targeted by RA (DERATGs). Subsequently, Disease Ontology, Gene Ontology, and the Kyoto Encyclopedia of Genes and Genomes were used to analyze DERATGs functionally. Gene Set Enrichment Analysis (GSEA) and Gene Set Variation Analysis (GSVA) were performed on the data from the gene expression matrix. Additionally, the protein-protein interaction network, transcription factor (TF)-targets, target-drug, microRNA (miRNA)-mRNA networks, and RNA-binding proteins (RBPs)-DERATGs correlation analyses were built. The CIBERSORT was used to evaluate the inflammatory immune state. The single-sample GSEA (ssGSEA) algorithm and differential analysis of DERATGs were used among the infiltration degree subtypes.

RESULTS

There were some correlations between the abundance of gut flora and the prevalence of RA. A total of 54 DERATGs were identified, mainly related to immune and inflammatory responses and immunodeficiency diseases. Through GSEA and GSVA analysis, we found pathway alterations related to metabolic regulations, autoimmune diseases, and immunodeficiency-related disorders. We obtained 20 hub genes and 2 subnetworks. Additionally, we found that 39 TFs, 174 drugs, 2310 miRNAs, and several RBPs were related to DERATGs. Mast, plasma, and naive B cells differed during immune infiltration. We discovered DERATGs' differences among subtypes using the ssGSEA algorithm and subtype grouping.

CONCLUSIONS

The findings of this study could help with RA diagnosis, prognosis, and targeted molecular treatment.

Association Between Herpes Simplex Virus II Infection and Rheumatoid Arthritis in US Adults: A Population-Based Propensity Score-Matching Study

BACKGROUND/OBJECTIVE

The potential correlation between herpes simplex virus (HSV) and human papillomavirus (HPV) infections and rheumatoid arthritis (RA) has not been definitively established. Further research is needed to determine the relationship between the development of RA and the presence of these viral infections.

METHODS

A case-control study was conducted with data from the National Health and Nutrition Examination Survey between 2009 and 2014. Our analysis examined the association between HSV I, HSV II, HPV oral polymerase chain reaction (PCR), HPV vaginal PCR, and RA. We identified adults aged 20 to 49 years with a primary diagnosis of RA using the National Health and Nutrition Examination Survey database codes (MCQ191 = 1 [years 2009-2010]; MCQ195 = 2 [years 2011-2014]) and excluded patients with incomplete data on key variables and primary outcomes.

RESULTS

The study included 8620 patients, with 150 patients diagnosed with RA and 1500 patients without RA. Patients with RA had a significantly higher prevalence of HSV II infection compared with those without RA (36.34% vs. 24.72%, p = 0.015) after propensity score matching. No significant differences were observed for HSV I, HPV oral PCR, and HPV vaginal PCR between the 2 groups. Patients with RA were older; were more likely to be female, obese, and non-Hispanic White; and had a higher prevalence of comorbidities than those without RA.

CONCLUSIONS

This population-based propensity score-matching study provides evidence of an association between HSV II infection and RA in US adults. Further research is needed to fully elucidate the relationship between viral infections and RA, with the aim of developing effective risk reduction strategies and innovative treatments for RA.

Rituximab exerts its anti-arthritic effects via inhibiting NF-κB/GM-CSF/iNOS signaling in B cells in a mouse model of collagen-induced arthritis

Rheumatoidarthritis (RA) is an autoimmune disease characterized by uncontrolled joint inflammation and damage to bone and cartilage. B cells are known to play a crucial role in the pathogenesis and development of arthritis. Previous studies have found that B cells may be a potential target for treating RA. Rituximab, a monoclonal antibody targeting B cells, has induced long-term clinical responses in RA. Collagen-induced arthritis (CIA) mouse model is a widely studied autoimmune model of RA. CIA mouse model was used to investigate the effect of rituximab on the RA severity in the mice. Following induction of CIA, animals were treated with rituximab (250 mg/kg/week) intraperitoneally on the days 28, 35, 42, 49, 56, and 63 after collagen induction. We investigated the effect of rituximab on NF-κB p65, IκBα, GM-CSF, MCP-1, iNOS, TNF-α, and IL-6 cells in splenic CD19⁺ and CD45R⁺ B cells using flow cytometry. We also assessed the effect of rituximab on NF-κB p65, GM-CSF, IκBα, MCP-1, iNOS, TNF-α, and IL-6 at mRNA levels using RT-PCR analyses of knee tissues. Rituximab treatment significantly decreased CD19⁺NF-κB p65⁺, CD45R⁺NF-κB p65⁺, CD19⁺GM-CSF⁺, CD45R⁺GM-CSF⁺, CD19⁺MCP-1⁺, CD45R⁺MCP-1⁺, CD19⁺TNF-α⁺, CD45R⁺TNF-α⁺, CD19⁺iNOS⁺, CD45R⁺iNOS⁺, CD19⁺IL-6⁺, and CD45R⁺IL-6⁺, and increased CD45R⁺IκBα⁺ in spleen cells of CIA mice. We further observed that rituximab treatment downregulated NF-κB p65, GM-CSF, MCP-1, iNOS, TNF-α, and IL-6, whereas it upregulated IκBα, mRNA level. All these findings suggest that rituximab may be a novel therapeutic target for the treatment of RA.

Chemokines and chemokine receptors as promising targets in rheumatoid arthritis

Rheumatoid arthritis (RA) is an autoimmune disease that commonly causes inflammation and bone destruction in multiple joints. Inflammatory cytokines, such as IL-6 and TNF-α, play important roles in RA development and pathogenesis. Biological therapies targeting these cytokines have revolutionized RA therapy. However, approximately 50% of the patients are non-responders to these therapies. Therefore, there is an ongoing need to identify new therapeutic targets and therapies for patients with RA. In this review, we focus on the pathogenic roles of chemokines and their G-protein-coupled receptors (GPCRs) in RA. Inflamed tissues in RA, such as the synovium, highly express various chemokines to promote leukocyte migration, tightly controlled by chemokine ligand-receptor interactions. Because the inhibition of these signaling pathways results in inflammatory response regulation, chemokines and their receptors could be promising targets for RA therapy. The blockade of various chemokines and/or their receptors has yielded prospective results in preclinical trials using animal models of inflammatory arthritis. However, some of these strategies have failed in clinical trials. Nonetheless, some blockades showed promising results in early-phase clinical trials, suggesting that chemokine ligand-receptor interactions remain a promising therapeutic target for RA and other autoimmune diseases.

Transcription factor KLF4 regulated STAT1 to promote M1 polarization of macrophages in rheumatoid arthritis

This study aimed to reveal the mechanism of transcription factor Kruppel-like factor 4 (KLF4) in regulating M1 polarization of macrophages in rheumatoid arthritis (RA) in order to induce inflammatory response. The results suggested that KLF4 overexpression promoted the M1 polarization of RAW 264.7 cells, increased STAT1 expression and up-regulated the phosphorylation level. After KLF4 silencing, the M1 polarization level was down-regulated. Besides, the induced M1 macrophages were co-cultured with articular chondrocytes. KLF4 overexpression further aggravated chondrocyte injury, increased the cell apoptosis rate and activated the inflammatory injury. However, pretreatment with STAT1 inhibitor Cerulomycin resisted the effect of KLF4, and significantly suppressed STAT1 expression and M1 polarization of cells. KLF4 overexpression aggravated synovial tissue injury in mouse joints, up-regulated the expression of inflammatory factors, and increased the levels of CD86 and STAT1.

It was discovered that transcription factor KLF4 promoted the transcription of STAT1 to regulate the M1 polarization of macrophages, thus aggravating the progression of RA and inflammatory response.

Physoxia alters human mesenchymal stem cell secretome

The human mesenchymal stem cell (hMSC) secretome has pleiotropic effects which underpin their therapeutic potential. hMSC serum-free conditioned media (SFCM) has been determined to contain a variety of cytokines with roles in regeneration and suppression of inflammation. Physiological oxygen (physoxia) has been demonstrated to impact upon a number of facets of hMSC biology and we hypothesized that the secretome would be similarly modified. We tested a range of oxygen conditions; 21% O₂ (air oxygen (AO)), 2% O₂ (intermittent hypoxia (IH)) and 2% O₂ Workstation (physoxia (P)) to evaluate their effect on hMSC secretome profiles. Total protein content of secretome was upregulated in IH and P (>3 fold vs AO) and IH (>1 fold vs P). Focused cytokine profiling indicated global upregulation in IH of all 31 biomolecules tested in comparison to AO and P with basic-nerve growth factor (bNGF) and granulocyte colony-stimulating factor (GCSF) (>3 fold vs AO) and bNGF and Rantes (>3 fold vs P) of note. Similarly, upregulation of interferon gamma-induced protein 10 (IP10) was noted in P (>3 fold vs AO). Interleukin-2 (IL2) and Rantes (in AO and P) and adiponectin, IL17a, and epidermal growth factor (EGF) (in AO only) were entirely absent or below detection limits. Quantitative analysis validated the pattern of IH-induced upregulation in vascular endothelial growth factor (VEGF), placental growth factor-1 (PIGF1), Tumor necrosis factor alpha (TNFa), IL2, IL4, and IL10 when compared to AO and P. In summary, modulation of environmental oxygen alters both secretome concentration and composition. This consideration will likely impact on delivering improved mechanistic understanding and potency effects of hMSC-based therapeutics.

Rheumatoid arthritis: Development after the emergence of a chemokine for neutrophils in the synovium

Rheumatoid arthritis (RA) may not be a multifactorial disease; it can be hypothesized that RA is developed through a series of events following a triggering event, which is the emergence of a chemokine for neutrophils in the synovium. IL-17A, secreted by infiltrated neutrophils, stimulates synoviocytes to produce CCL20, which attracts various CCR6-expressing cells, including Th17 cells. Monocytes (macrophages) appear after neutrophil infiltration according to the natural course of inflammation and secrete IL-1β and TNFα. Then, IL-17A, IL-1β, and TNFα stimulate synoviocytes to produce CCL20, amplifying the inflammation. Varieties of chemokines secreted by infiltrating cells accumulate in the synovium and induce synoviocyte proliferation by binding to the corresponding G protein-coupled receptors, thus expanding the synovial tissue. CCL20 in this tissue attracts circulating monocytes that express both CCR6 and receptor activator of NF-κB (RANK), which differentiate into osteoclasts in the presence of RANKL. In this way, pannus is formed, and bone destruction begins.

Eotaxin-1/CCL11 is involved in cell migration in rheumatoid arthritis

Eotaxin-1 (CCL11) induces the migration of different leukocyte types by interacting with CCR3. In rheumatoid arthritis (RA), fibroblast-like synoviocytes (FLS) are pathogenic effectors and a major CCR3-expressing cell. The aim of this study was to investigate the expression and function of CCL11 in RA FLS. The expression of CCL11 and CCR3 was evaluated by ELISA, immunofluorescence and quantitative PCR analysis. The CCL11 levels in serum and synovial fluids (SFs) from RA patients were significantly higher than those in serum from healthy controls and SFs from osteoarthritis patients. CCL11 and CCR3 were expressed in the RA synovial tissue lining layers. The secretion of CCL11 in RA FLS-conditioned medium and the mRNA expression of CCL11 and CCR3 were induced by TNF-α. Furthermore, CCL11 induced the mRNA expression of CCL11 and CCR3. Application of a CCR3 antagonist reduced TNF-α-induced CCL11 secretion from RA FLS. CCL11 induced the migration of RA FLS and monocytes. RA FLS migration was decreased by treatment with CCL11 siRNA. The migration of monocytes to medium conditioned with CCL11 siRNA-transfected and TNF-α-stimulated RA FLS was reduced. These data indicate that the self-amplification of CCL11 via CCR3 may play an important role in cell migration in RA.

Chemokine Receptor 5 Antagonism Causes Reduction in Joint Inflammation in a Collagen-Induced Arthritis Mouse Model

Rheumatoid arthritis (RA) is a chronic inflammatory disease mainly affecting the synovial joints. A highly potent antagonist of C-C chemokine receptor 5 (CCR5), maraviroc (MVC), plays an essential role in treating several infectious diseases but has not yet been evaluated for its potential effects on RA development. This study focused on evaluating the therapeutic potential of MVC on collagen-induced arthritis (CIA) in DBA/1J mice. Following CIA induction, animals were treated intraperitoneally with MVC (50 mg/kg) daily from day 21 until day 35 and evaluated for clinical score and histopathological changes in arthritic inflammation. We further investigated the effect of MVC on Th9 (IL-9, IRF-4, and GATA3) and Th17 (IL-21R, IL-17A, and RORγT) cells, TNF-α, and RANTES in CD8+ T cells in the spleen using flow cytometry. We also assessed the effect of MVC on mRNA and protein levels of IL-9, IL-17A, RORγT, and GATA3 in knee tissues using RT-PCR and western blot analysis. MVC treatment in CIA mice attenuated the clinical and histological severity of inflammatory arthritis, and it substantially decreased IL-9, IRF4, IL-21R, IL-17A, RORγT, TNF-α, and RANTES production but increased GATA3 production in CD8+ T cells. We further observed that MVC treatment decreased IL-9, IL-17A, and RORγt mRNA and protein levels and increased those of GATA3. This study elucidates the capacity of MVC to ameliorate the clinical and histological signs of CIA by reducing pro-inflammatory responses, suggesting that MVC may have novel therapeutic uses in the treatment of RA.

Inhibition of hepatocyte growth factor/c-Met signalling abrogates joint destruction by suppressing monocyte migration in rheumatoid arthritis

OBJECTIVES

To determine the expression of hepatocyte growth factor (HGF) in RA biological fluids, the role of HGF in monocyte migration and the therapeutic effect of the c-Met inhibitor savolitinib in an arthritis model mice.

METHODS

HGF/c-Met expression in serum, SF and synovial tissues (STs) obtained from RA patients and controls, as well as RA fibroblast-like synoviocytes (FLSs), was evaluated by ELISA and immunostaining. To determine the function of HGF in RA SF, we preincubated RA SF with a neutralizing anti-HGF antibody and measured the chemotactic ability of a human acute monocytic leukaemia cell line (THP-1). Additionally, examinations were conducted of SKG mice treated with savolitinib for 4 weeks.

RESULTS

HGF levels in serum from RA patients were significantly higher than those in the controls and were decreased by drug treatment for 24 weeks. Additionally, the HGF level in SF from RA patients was higher than that in SF from OA patients. HGF and c-Met expression was also noted in RA STs. Stimulation of RA FLSs with TNF-α increased HGF/c-Met expression in a concentration-dependent manner, and c-Met signal inhibition suppressed production of fractalkine/CX3CL1 and macrophage inflammatory protein-1α/CCL3. When HGF was removed by immunoprecipitation, migration of THP-1 in RA SF was suppressed. In SKG mice, savolitinib significantly suppressed ankle bone destruction on µCT, with an associated reduction in the number of tartrate-resistant acid phosphatase-positive osteoclasts.

CONCLUSION

HGF produced by inflammation in synovium of RA patients activates monocyte migration to synovium and promotes bone destruction via a chemotactic effect and enhanced chemokine production.

Prevention of CaCl2-induced aortic inflammation and subsequent aneurysm formation by the CCL3-CCR5 axis

Inflammatory mediators such as cytokines and chemokines are crucially involved in the development of abdominal aortic aneurysm (AAA). Here we report that CaCl₂ application into abdominal aorta induces AAA with intra-aortic infiltration of macrophages as well as enhanced expression of chemokine (C-C motif) ligand 3 (CCL3) and MMP-9. Moreover, infiltrating macrophages express C-C chemokine receptor 5 (CCR5, a specific receptor for CCL3) and MMP-9. Both Ccl3^−/− mice and Ccr5^−/− but not Ccr1^−/− mice exhibit exaggerated CaCl₂-inducced AAA with augmented macrophage infiltration and MMP-9 expression. Similar observations are also obtained on an angiotensin II-induced AAA model. Immunoneutralization of CCL3 mimics the phenotypes observed in CaCl₂-treated Ccl3^−/− mice. On the contrary, CCL3 treatment attenuates CaCl₂-induced AAA in both wild-type and Ccl3^−/− mice. Consistently, we find that the CCL3–CCR5 axis suppresses PMA-induced enhancement of MMP-9 expression in macrophages. Thus, CCL3 can be effective to prevent the development of CaCl₂-induced AAA by suppressing MMP-9 expression.

Inflammatory cytokines and chemokines are involved in the development of abdominal aortic aneurysm (AAA). Here the authors show that CCL3 prevents the development of CaCl₂-induced AAA by suppressing MMP-9 expression.

Protective effect of a new hyaluronic acid -carnosine conjugate on the modulation of the inflammatory response in mice subjected to collagen-induced arthritis

Several studies demonstrated the pharmacological actions of carnosine as well as hyaluronic acid (HA) during joint inflammation. In that regard, the aim of this study was to investigate the protective effect of a new HA -Carnosine conjugate (FidHycarn) on the modulation of the inflammatory response in mice subjected to collagen-induced arthritis (CIA). CIA was induced by two intradermal injections of 100 μl of an emulsion of collagen (CII) and complete Freund's adjuvant (CFA) at the base of the tail on day 0 and 21. At 35 day post CIA induction, the animals were sacrificed. CII injection caused erythema and edema in the hind paws, histological alterations with erosion of the joint cartilage as well as behavioral changes. Oral treatment with FidHycarn starting at the onset of arthritis (day 25) ameliorated the clinical signs, improved behavioral deficits as well as decreased histological and radiographic alterations. The degree of oxidative damage evaluated by inducible nitric oxide synthase (iNOS), nitrotyrosine, poly-ADP-ribose (PAR) expressions and malondialdehyde (MDA) levels, was also significantly reduced in Carnosine+HA association and FidHycarn treated mice. Moreover, the levels of proinflammatory cytokines and chemokines and cyclo-oxygenase COX-2 enzyme were also more significantly reduced by Carnosine+HA and FidHycarn compared to carnosine alone. However, interestingly, in some cases, the effects of FidHycarn were more important than Carnosine+HA association and not statistically different to methotrexate (MTX) used as positive control. Thus, the conjugation of Carnosine with HA (FidHycarn) could represent an interesting therapeutic strategy to combat arthritis disorders.

Chemokines: A Potential Therapeutic Target to Suppress Autoimmune Arthritis

BACKGROUND

Chemokines are a family of low molecular weight proteins that induce chemotaxis of inflammatory cells, which mainly depends on the recognition of a chemo-attractant gradient and interaction with the substratum. In Rheumatoid Arthritis (RA), abundant chemokines are expressed in synovial tissue, cause inflammatory cells migration into the inflamed joint that necessitates the formation of new blood vessels i.e. angiogenesis. Over the decades, studies showed that continuous inflammation may lead to the loss of tissue architecture and function, causing severe disability and cartilage destruction. In spite of the advancement of modern drug therapy, thousands of arthritic patients suffer mortality and morbidity globally. Thus, there is an urgent need for the development of novel therapeutic agents for the treatment of RA.

METHODS

This review is carried out throughout a non-systematic search of the accessible literature, will provide an overview of the current information of chemokine in RA and also exploring the future perspective of the vital role of targeting chemokine in RA treatment.

RESULTS

Since, chemokines are associated with inflammatory cells/leucocyte migration at the site of inflammation in chronic inflammatory diseases and hence, blockade or interference with chemokines activity showing a potential approach for the development of new anti-inflammatory agents. Currently, results obtained from both preclinical and clinical studies showed significant improvement in arthritis.

CONCLUSION

This review summarizes the role of chemokines and their receptors in the pathogenesis of RA and also indicates possible interactions of chemokines/receptors with various synthetic and natural compounds that may be used as a potential therapeutic target in the future for the treatment of RA.

Euphorbia bicolor (Euphorbiaceae) Latex Extract Reduces Inflammatory Cytokines and Oxidative Stress in a Rat Model of Orofacial Pain

Recent studies have reported that the transient receptor potential V1 ion channel (TRPV1), a pain generator on sensory neurons, is activated and potentiated by NADPH oxidase-generated reactive oxygen species (ROS). ROS are increased by advanced oxidation protein products (AOPPs), which activate NADPH oxidase by upregulating Nox4 expression. Our previous studies reported that Euphorbia bicolor (Euphorbiaceae) latex extract induced peripheral analgesia, partly via TRPV1, in hindpaw-inflamed male and female rats. The present study reports that E. bicolor latex extract also can evoke analgesia via reduction of oxidative stress biomarkers and proinflammatory cytokines/chemokines in a rat model of orofacial pain. Male and female rats were injected with complete Freund's adjuvant (CFA) into the left vibrissal pad to induce orofacial inflammation, and mechanical allodynia was measured by the von Frey method. Twenty-four hours later, rats received one injection of E. bicolor latex extract or vehicle into the inflamed vibrissal pad. Mechanical sensitivity was reassessed at 1, 6, 24, and/or 72 hours. Trigeminal ganglia and trunk blood were collected at each time point. In the trigeminal ganglia, ROS were quantified using 2',7'-dichlorodihydrofluorescein diacetate dye, Nox4 protein was quantified by Western blots, and cytokines/chemokines were quantified using a cytokine array. AOPPs were quantified in trunk blood using a spectrophotometric assay. E. bicolor latex extract significantly reduced orofacial mechanical allodynia in male and female rats at 24 and 72 hours, respectively. ROS, Nox4, and proinflammatory cytokines/chemokines were significantly reduced in the trigeminal ganglia, and plasma AOPP was significantly reduced in the trunk blood of extract-treated compared to vehicle-treated rats. In vitro assays indicate that E. bicolor latex extract possessed antioxidant activities by scavenging free radicals. Together our data indicate that the phytochemicals in E. bicolor latex may serve as novel therapeutics for treating oxidative stress-induced pain conditions.

B cells inhibit bone formation in rheumatoid arthritis by suppressing osteoblast differentiation

The function of B cells in osteoblast (OB) dysfunction in rheumatoid arthritis (RA) has not been well-studied. Here we show that B cells are enriched in the subchondral and endosteal bone marrow (BM) areas adjacent to osteocalcin+ OBs in two murine RA models: collagen-induced arthritis and the TNF-transgenic mice. Subchondral BM B cells in RA mice express high levels of OB inhibitors, CCL3 and TNF, and inhibit OB differentiation by activating ERK and NF-κB signaling pathways. The inhibitory effect of RA B cells on OB differentiation is blocked by CCL3 and TNF neutralization, and deletion of CCL3 and TNF in RA B cells completely rescues OB function in vivo, while B cell depletion attenuates bone erosion and OB inhibition in RA mice. Lastly, B cells from RA patients express CCL3 and TNF and inhibit OB differentiation, with these effects ameliorated by CCL3 and TNF neutralization. Thus, B cells inhibit bone formation in RA by producing multiple OB inhibitors.

Nicorandil and theophylline can protect experimental rats against complete Freund's adjuvant-induced rheumatoid arthritis through modulation of JAK/STAT/RANKL signaling pathway

Signaling pathways are interesting fields of study of pathogenesis and treatment trials. We elucidated the possible protective effects of nicorandil (15mg/kg/day) and theophylline (20mg/kg/day) on experimentally-induced RA, focusing on the role of JAK (Janus Kinase) / STAT (Signal Transducer and Activator of Transcription) / RANKL (Receptor Activator of Nuclear factor-Kappa B Ligand) / cytokine signaling pathway. Four sets of experiments were performed. First, effect of test agents on normal animals was evaluated. Second, effect of test agents was evaluated on Complete Freund's Adjuvant (CFA; 0.3ml, s.c.)-induced RA to investigate anti-arthritic effect. Third, effect of test agents was evaluated on growth hormone (GH; 2mg/kg/day, s.c.)-induced stimulation of JAK/STAT/RANKL/cytokine signaling pathway to investigate the role of this signaling pathway in their anti-arthritic effect. Fourth, the effect of test agents was performed on CFA/GH-induced RA. To fulfill this purpose, serum anti-citrullinated peptide antibody (ACPA), interleukin-6 (IL-6), and cartilage oligomeric matrix protein (COMP), together with tissue JAK2, STAT3, RANKL, inducible and endothelial nitric oxide synthases (iNOS and eNOS) as well as macrophage inflammatory protein (MIP_1α) were estimated using ELISA, Western blotting and PCR techniques, confirmed by a histopathological study. Test agents significantly corrected JAK2, STAT3, RANKL and IL-6 values in animals receiving GH. Additionally, test agents could correct ACPA, IL-6, COMP, JAK2, STAT3, RANKL, iNOS, eNOS and MIP_1α levels compared with the respective CFA or CFA/GH controls. These results conclude that nicorandil and theophylline have good anti-arthritic effects related to modulation of JAK/STAT/RANKL signaling pathway. Further clinical trials are claimed.

The impact of hypoxic-ischemic brain injury on stem cell mobilization, migration, adhesion, and proliferation

Neonatal hypoxic-ischemic encephalopathy continues to be a significant cause of death or neurodevelopmental delays despite standard use of therapeutic hypothermia. The use of stem cell transplantation has recently emerged as a promising supplemental therapy to further improve the outcomes of infants with hypoxic-ischemic encephalopathy. After the injury, the brain releases several chemical mediators, many of which communicate directly with stem cells to encourage mobilization, migration, cell adhesion and differentiation. This manuscript reviews the biomarkers that are released from the injured brain and their interactions with stem cells, providing insight regarding how their upregulation could improve stem cell therapy by maximizing cell delivery to the injured tissue.

Dried plum alleviates symptoms of inflammatory arthritis in TNF transgenic mice

Dried plum (DP), a rich source of polyphenols has been shown to have bone-preserving properties in both animal models of osteoporosis and postmenopausal women. We evaluated if DP alleviated the destruction of joints in transgenic mice (TG) that overexpress human tumor necrosis factor (TNF), a genetic model of rheumatoid arthritis (RA). A four-week treatment of 20% DP diet in TG slowed the onset of arthritis and reduced bone erosions in the joints compared to TG on a regular diet. This was associated with fewer tartrate-resistant acid phosphatase (TRAP) positive cells, suggesting decreased osteoclastogenesis. A DP diet also produced significant protection of articular cartilage and reduction of synovitis. Cultures of human synovial fibroblast in the presence of TNF showed a significant increase in inflammatory interleukin (IL)-1β, chemokines (monocyte chemoattractant protein-1: MCP1 & macrophage inflammatory protein-1 alpha: MIP1α), cartilage matrix metalloproteinases (MMP1&3), and an osteoclastogenic cytokine (receptor activator of nuclear factor-κB ligand: RANKL) compared to controls. Addition of neochlorogenic acid (NC), a major polyphenol in DP to these cultures resulted in down-regulation of these genes. In the cultures of mouse bone marrow macrophage, NC also repressed TNF-induced formation of osteoclasts and mRNA levels of cathepsin K and MMP9 through inhibition of nuclear factor of activated T-cells, cytoplasmic 1 (NFATc1) expression and nuclear factor kappa B (NF-κB) activation. Our data suggested that dietary supplementation with DP inhibited TNF singling; leading to decreased erosions of bone and articular cartilage as well as synovitis.

Mig-6 deficiency cooperates with oncogenic Kras to promote mouse lung tumorigenesis

OBJECTIVES

Lung cancer is the leading cause of cancer related deaths worldwide and mutation activating KRAS is one of the most frequent mutations found in lung adenocarcinoma. Identifying regulators of KRAS may aid in the development of therapies to treat this disease. The mitogen-induced gene 6, MIG-6, is a small adaptor protein modulating signaling in cells to regulate the growth and differentiation in multiple tissues. Here, we investigated the role of Mig-6 in regulating adenocarcinoma progression in the lungs of genetically engineered mice with activation of Kras.

MATERIALS AND METHODS

Using the CCSPCre mouse to specifically activate expression of the oncogenic KrasG12D in Club cells, we investigated the expression of Mig-6 in CCSPCreKrasG12D-induced lung tumors. To determine the role of Mig-6 in KrasG12D-induced lung tumorigenesis, Mig-6 was conditionally ablated in the Club cells by breeding Mig6f/f mice to CCSPCreKrasG12D mice, yielding CCSPCreMig-6d/dKrasG12D mice (Mig-6d/dKrasG12D).

RESULTS

We found that Mig-6 expression is decreased in CCSPCreKrasG12D-induced lung tumors. Ablation of Mig-6 in the KrasG12D background led to enhanced tumorigenesis and reduced life expectancy. During tumor progression, there was increased airway hyperplasia, a heightened inflammatory response, reduced apoptosis in KrasG12D mouse lungs, and an increase of total and phosphorylated ERBB4 protein levels. Mechanistically, Mig-6 deficiency attenuates the cell apoptosis of lung tumor expressing KRASG12D partially through activating the ErbB4 pathway.

CONCLUSIONS

In summary, Mig-6 deficiency promotes the development of KrasG12D-induced lung adenoma through reducing the cell apoptosis in KrasG12D mouse lungs partially by activating the ErbB4 pathway.

Synovial cellular and molecular markers in rheumatoid arthritis

The profound alterations in the structure, cellular composition, and function of synovial tissue in rheumatoid arthritis (RA) are the basis for the persistent inflammation and cumulative joint destruction that are hallmarks of this disease. In RA, the synovium develops characteristics of a tertiary lymphoid organ, with extensive infiltration of lymphocytes and myeloid cells. Concurrently, the fibroblast-like synoviocytes undergo massive hyperplasia and acquire a tissue-invasive phenotype. In this review, we summarize key components of these processes, focusing on recently-described roles of selected molecular markers of these cellular components of RA synovitis.

Wu-Tou Decoction in Rheumatoid Arthritis: Integrating Network Pharmacology and In Vivo Pharmacological Evaluation

Purpose: This study aimed to explore underlying action mechanism of Wu-Tou decoction (WTD) in rheumatoid arthritis (RA) through network pharmacology prediction and experimental verification. Methods: Chemical compounds and human target proteins of WTD as well as RA-related human genes were obtained from TCM Database @ Taiwan, PubChem and GenBank, respectively. Subsequently, molecular networks and canonical pathways presumably involved in the treatment of WTD on RA were generated by ingenuity pathway analysis (IPA) software. Furthermore, experimental validation was carried out with MIP-1β-induced U937 cell model and collagen induced arthritis (CIA) rat model. Results: CCR5 signaling pathway in macrophages was shown to be the top one shared signaling pathway associated with both cell immune response and cytokine signaling. In addition, protein kinase C (PKC) δ and p38 in this pathway were treated as target proteins of WTD in RA. In vitro experiments indicated that WTD inhibited MIP-1β-induced production of TNF-α, MIP-1α, and RANTES as well as phosphorylation of CCR5, PKC δ, and p38 in U937 cells. WTD treatment maintained the inhibitory effects on production of TNF-α and RANTES in MIP-1β-induced U937 cells after CCR5 knockdown. In vivo experiments demonstrated that WTD ameliorated symptoms in CIA rats, decreased the levels of IL-1β, IL-2, IL-6, TNF-α, MIP-1α, MIP-2, RANTES, and IP-10 in serum of CIA rats, as well as mRNA levels of MIP-1α, MIP-2, RANTES, and IP-10 in ankle joints of CIA rats. Furthermore, WTD also lowered the phosphorylation levels of CCR5, PKC δ and p38 in both ankle joints and macrophages in ankle joints from CIA rats. Conclusion: It was demonstrated in this research that WTD played a role in inhibiting inflammatory response in RA which was closely connected with the modulation effect of WTD on CCR5 signaling pathway in macrophages.

CCL3 and MMP-9 are induced by TL1A during death receptor 3 (TNFRSF25)-dependent osteoclast function and systemic bone loss

Reduced bone density and secondary osteoporosis, resulting in increased risk of fracture, is a significant complicating factor in the inflammatory arthritides. While the exact etiology of systemic bone loss is not fully elucidated, recent insights into the tumor necrosis factor super family (TNFSF) revealed a potential role for death receptor 3 (DR3/TNFRSF25) and one of its ligands, TNF-like protein 1A (TL1A/TNFSF15). The mechanisms by which DR3/TL1A signalling modulates bone loss are unclear. We investigated the effect of DR3/TL1A signalling upon osteoclast-dependent chemokine and MMP production to unravel novel mechanisms whereby this pathway regulates OC formation and OC-dependent bone resorption. Collagen induced arthritis (CIA) was established in DR3^wt and DR3^ko mice, joints were sectioned and analysed histologically for bone damage while systemic trabecular bone loss distal to the affected joints was compared by micro-CT. Ablation of DR3 protected DBA/1 mice against the development and progression of CIA. In DR3^ko, joints of the ankle and mid-foot were almost free of bone erosions and long bones of mice with CIA were protected against systemic trabecular bone loss. In vitro, expression of DR3 was confirmed on primary human CD14⁺ osteoclast precursors by flow cytometry. These cells were treated with TL1A in osteoclast differentiation medium and TRAP⁺ osteoclasts, bone resorption, levels of osteoclast-associated chemokines (CCL3, CCL2 and CXCL8) and MMP-9 measured. TL1A intensified human osteoclast differentiation and bone resorption and increased osteoclast-associated production of CCL3 and MMP-9. Our data reveals the DR3 pathway as an attractive therapeutic target to combat adverse bone pathology associated with inflammatory arthritis. We demonstrate that DR3 is critical in the pathogenesis of murine CIA and associated secondary osteoporosis. Furthermore, we identify a novel mechanism by which the DR3/TL1A pathway directly enhances human OC formation and resorptive activity, controlling expression and activation of CCL3 and MMP-9.

Inflammatory Cell Migration in Rheumatoid Arthritis: A Comprehensive Review

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease that primarily affects the joints. Self-reactive B and T lymphocytes cooperate to promote antibody responses against self proteins and are major drivers of disease. T lymphocytes also promote RA independently of B lymphocytes mainly through the production of key inflammatory cytokines, such as IL-17, that promote pathology. While the innate signals that initiate self-reactive adaptive immune responses are poorly understood, the disease is predominantly caused by inflammatory cellular infiltration and accumulation in articular tissues, and by bone erosions driven by bone-resorbing osteoclasts. Osteoclasts are giant multinucleated cells formed by the fusion of multiple myeloid cells that require short-range signals, such as the cytokines MCSF and RANKL, for undergoing differentiation. The recruitment and positioning of osteoclast precursors to sites of osteoclast differentiation by chemoattractants is an important point of control for osteoclastogenesis and bone resorption. Recently, the GPCR EBI2 and its oxysterol ligand 7a, 25 dihydroxycholesterol, were identified as important regulators of osteoclast precursor positioning in proximity to bone surfaces and of osteoclast differentiation under homeostasis. In chronic inflammatory diseases like RA, osteoclast differentiation is also driven by inflammatory cytokines such as TNFa and IL-1, and can occur independently of RANKL. Finally, there is growing evidence that the chemotactic signals guiding osteoclast precursors to inflamed articular sites contribute to disease and are of great interest. Furthering our understanding of the complex osteoimmune cell interactions should provide new avenues of therapeutic intervention for RA.

Activation of the cholinergic anti-inflammatory system by nicotine attenuates arthritis via suppression of macrophage migration

Activation of the cholinergic anti-inflammatory pathway (CAP), which relies on the alpha-7 nicotinic acetylcholine receptor, has been reported to reduce proinflammatory cytokine levels in experimental arthritis. To gain more insight regarding the role of the CAP in the pathogenesis of arthritis, the present study focused on the modulation of macrophage infiltration. In a mouse model of collagen‑induced arthritis (CIA), nicotine and vagotomy were used to stimulate and inhibit the CAP, respectively. Subsequently, arthritic scores were measured and histopathological assessment of joint sections was conducted. Cluster of differentiation (CD)11b‑positive macrophages in the synovium were studied by immunofluorescence histochemistry. The serum levels of chemokines, including macrophage inflammatory protein (MIP)‑1α, monocyte chemoattractant protein (MCP)‑1 and MIP‑2 were evaluated by ELISA. Furthermore, the expression levels of C‑C chemokine receptor (CCR)2 and intercellular adhesion molecule (ICAM)‑1 in the synovium were evaluated by immunohistochemical staining. The results indicated that treatment with nicotine significantly attenuated the clinical and histopathological changes associated with arthritis, reduced CD11b‑positive macrophages in the synovium, and downregulated the serum expression levels of MIP‑1α and MCP‑1. Conversely, vagotomy aggravated arthritis and upregulated the expression levels of MCP‑1. However, MIP‑2 expression did not differ among the control, CIA, vagotomy and nicotine groups. In addition, the expression levels of CCR2 were reduced in the nicotine group; however, they were increased in the vagotomy group compared with in the untreated CIA group. The expression levels of ICAM‑1 in the synovium were also influenced by activation of the CAP. Taken together, the present results indicated that nicotine‑induced activation of the CAP in mice with CIA may reduce the number of macrophages in the synovium, which may serve a role in alleviating arthritis in mice.

Characterization of death receptor 3-dependent aortic changes during inflammatory arthritis

Murine collagen-induced arthritis (mCIA) is characterized by decreased vascular constriction responses and increased MMP-9. Here, we describe additional histological alterations within the aorta and surrounding perivascular adipose tissue (PVAT), study the role of PVAT in constriction response, and investigate the potential involvement of death receptor 3 (DR3). mCIA was induced in wild-type (WT) and DR3-/- mice with nonimmunized, age-matched controls. Vascular function was determined in isolated aortic rings ±PVAT, using isometric tension myography, in response to cumulative serotonin concentrations. Cellular expression of F4/80 (macrophages), Ly6G (neutrophils), DR3, and MMP-9 was determined using immunohistochemistry. In WTs, arthritis-induced vascular dysfunction was associated with increased F4/80+ macrophages and increased DR3 expression in the aorta and PVAT. MMP-9 was also up-regulated in PVAT, but did not correlate with alterations of PVAT intact constriction. DR3-/- mice inherently showed increased leukocyte numbers and MMP-9 expression in the PVAT, but retained the same nonarthritic constriction response as DR3WT mice ±PVAT. Arthritic DR3-/- mice had a worsened constriction response than DR3WT and showed an influx of neutrophils to the aorta and PVAT. Macrophage numbers were also up-regulated in DR3-/- PVAT. Despite this influx, PVAT intact DR3-/- constriction responses were restored to the same level as DR3WT. Impaired vascular constriction in inflammatory arthritis occurs independently of total MMP-9 levels, but correlates with macrophage and neutrophil ingress. Ablating DR3 worsens the associated vasculature dysfunction, however, DR3-/- PVAT is able to protect the aorta against aberrant vasoconstriction caused in this model.

Elevation of Activated Platelet-Dependent Chemokines in Patients With Anti-CD20 Monoclonal Antibody (Rituximab)−Treated Non-Hodgkin's Lymphoma

.ocn.ne.jp. This study measured and compared levels of some chemokines in patients with rituximab-treated non-Hodgkin lymphoma because they may participate in the mechanism of efficacy of rituximab in non-Hodgkin lymphoma patients. Monocytic chemotactant protein-1, RANTES (regulated on activation, normally T-cell expressed and secreted), eotaxin, interleukin-8, neutrophil-activating protein-78, stromal cell-derived factor-1, and growth-regulating oncogene-α in patients with rituximab-treated non-Hodgkin lymphoma were measured by enzyme-linked immunosorbent assay. Levels of RANTES were higher in non-Hodgkin lymphoma patients than in controls. Levels of monocytic chemotactant protein-1, RANTES, and neutrophil-activating protein-78 were significantly elevated before and after chemotherapy with rituximab treatment. However, the level of stromal cell-derived factor-1 did not exhibit a significant change. Before to after chemotherapy without rituximab treatment, all chemokine levels did not exhibit significant changes. These findings suggest that activated platelet-dependent chemokines such as RANTES and neutrophil-activating protein-78 may modulate the efficacy of rituximab in antibody-dependent cellular cytotoxity.

Comorbidities of Psoriasis - Exploring the Links by Network Approach

Increasing epidemiological studies in patients with psoriasis report the frequent occurrence of one or more associated disorders. Psoriasis is associated with multiple comorbidities including autoimmune disease, neurological disorders, cardiometabolic diseases and inflammatory-bowel disease. An integrated system biology approach is utilized to decipher the molecular alliance of psoriasis with its comorbidities. An unbiased integrative network medicine methodology is adopted for the investigation of diseasome, biological process and pathways of five most common psoriasis associated comorbidities. A significant overlap was observed between genes acting in similar direction in psoriasis and its comorbidities proving the mandatory occurrence of either one of its comorbidities. The biological processes involved in inflammatory response and cell signaling formed a common basis between psoriasis and its associated comorbidities. The pathway analysis revealed the presence of few common pathways such as angiogenesis and few uncommon pathways which includes CCKR signaling map and gonadotrophin-realising hormone receptor pathway overlapping in all the comorbidities. The work shed light on few common genes and pathways that were previously overlooked. These fruitful targets may serve as a starting point for diagnosis and/or treatment of psoriasis comorbidities. The current research provides an evidence for the existence of shared component hypothesis between psoriasis and its comorbidities.

C1q Modulates the Response to TLR7 Stimulation by Pristane-Primed Macrophages: Implications for Pristane-Induced Lupus

The complement component C1q is known to play a controversial role in the pathogenesis of systemic lupus erythematosus, but the underlying mechanisms remain poorly understood. Intraperitoneal injection of pristane induces a lupus-like syndrome whose pathogenesis implicates the secretion of type I IFN by CD11b(+) Ly6C(high) inflammatory monocytes in a TLR7-dependent fashion. C1q was also shown to influence the secretion of IFN-α. In this study, we explored whether C1q deficiency could affect pristane-induced lupus. Surprisingly, C1qa(-/-) mice developed lower titers of circulating Abs and milder arthritis compared with the controls. In keeping with the clinical scores, 2 wk after pristane injection the peritoneal recruitment of CD11b(+) Ly6C(high) inflammatory monocytes in C1qa(-/-) mice was impaired. Furthermore, C1q-deficient pristane-primed resident peritoneal macrophages secreted significantly less CCL3, CCL2, CXCL1, and IL-6 when stimulated in vitro with TLR7 ligand. Replenishing C1q in vivo during the pristane-priming phase rectified this defect. Conversely, pristane-primed macrophages from C3-deficient mice did not show impaired cytokine production. These findings demonstrate that C1q deficiency impairs the TLR7-dependent chemokine production by pristane-primed peritoneal macrophages and suggest that C1q, and not C3, is involved in the handling of pristane by phagocytic cells, which is required to trigger disease in this model.

Interleukin-27 re-educates intratumoral myeloid cells and down-regulates stemness genes in non-small cell lung cancer

Current therapies for Non-Small Cell Lung Cancer (NSCLC) still fail to significantly increase its survival rate. Here we asked whether Interleukin(IL)-27, which has revealed powerful antitumor activity and is toxicity-free in humans, is a promising therapeutic choice for NSCLC patients.

IL-27's effects were tested on Adenocarcinoma (AC) and Squamous Cell Carcinoma (SCC) cell lines and xenograft models. IL-27Receptor(R) expression was assessed in lung tissues from 78 NSCLC patients.

In vitro, IL-27 was ineffective on cancer cell proliferation or apoptosis, but fostered CXCL3/GROγ/MIP2β expression. In vitro and in vivo, IL-27 down-regulated stemness-related genes, namely SONIC HEDGEHOG in AC cells, and OCT4A, SOX2, NOTCH1, KLF4 along with Nestin, SNAI1/SNAIL, SNAI2/SLUG and ZEB1, in SCC cells. In vivo, IL-27 hampered both AC and SCC tumor growth in association with a prominent granulocyte- and macrophage-driven colliquative necrosis, CXCL3 production, and a reduced pluripotency- and EMT-related gene expression. Myeloablation of tumor-bearing hosts mostly abolished IL-27's antitumor effects. In clinical samples, IL-27R expression was found in AC, SCC, pre-cancerous lesions and tumor infiltrating myeloid cells, and correlated with advanced stages of disease.

Our data suggest that even immunocompromised or advancer NSCLC patients may benefit from IL-27's antitumor properties based on its ability to drive myeloid cells towards antitumor activities, and down-regulate stemness- and EMT-related genes in cancer cells.

Successes and failures of chemokine-pathway targeting in rheumatoid arthritis

Chemokines and chemokine receptors are involved in leukocyte recruitment and angiogenesis underlying the pathogenesis of rheumatoid arthritis (RA) and other inflammatory rheumatic diseases. Numerous chemokines, along with both conventional and atypical cell-surface chemokine receptors, are found in inflamed synovia. Preclinical studies carried out in animal models of arthritis involving agents targeting chemokines and chemokine receptors have yielded promising results. However, most human trials of treatment of RA with antibodies and synthetic compounds targeting chemokine signalling have failed to show clinical improvements. Chemokines can have overlapping actions, and their activities can be altered by chemical modification or proteolytic degradation. Effective targeting of chemokine pathways must take acount of these properties, and can also require high levels of receptor occupancy by therapeutic agents to prevent signalling. CCR1 is a promising target for chemokine-receptor blockade.

A disintegrin and metalloprotease-10 is correlated with disease activity and mediates monocyte migration and adhesion in rheumatoid arthritis

A disintegrin and metalloproteases (ADAMs) are a family of proteins that have been reported to be involved in several inflammatory conditions. We examined the secretion of ADAM-10 in biological fluids from patients with rheumatoid arthritis (RA) and the role it plays in monocyte migration. ADAM-10 levels were measured using enzyme-linked immunosorbent assays and immunofluorescence. To examine the role of ADAM-10 in RA synovial fluids (SFs), we studied THP-1 (human acute monocyte leukemia cell line) and monocyte chemotaxis. To determine whether ADAM-10 plays a role in cell proliferation in the RA synovium, we assayed the proliferation of ADAM-10 small interfering RNA (siRNA)-transfected RA fibroblast-like synoviocytes (FLSs). The ADAM-10 level in RA serum was significantly higher than that in normal serum and was correlated with a disease activity score of 28. ADAM-10-depleted RA SFs showed a decrease in THP-1 and monocyte migratory activity compared with that of sham-depleted controls. ADAM-10 siRNA inhibited monocyte adhesion to RA FLSs. Finally, blocking ADAM-10 secretion in RA FLSs resulted in decreased production of fractalkine/CX3CL1 and vascular endothelial cell growth factor. These data indicate that ADAM-10 plays a role in monocyte migration in RA and suggest that targeting ADAM-10 may provide a method of decreasing inflammation and potentially treating other inflammatory diseases.

CCL3 serves as a potential plasma biomarker in knee degeneration (osteoarthritis)

OBJECTIVE

To explore the ability of chemokines in plasma to detect the presence of pre-X-rays defined knee degeneration and the extent (burden).

METHODS

A total of 181 subjects (75 control subjects, 47 pre-X-KD patients and 50 X-KOA patients) were included and subdivided into three subgroups. Articular cartilage loss in pre-X-KD patients were scored on the basis of the ICRS classification during the arthroscopy or documented on MRI with chondral WORMS. The severity of X-KOA was graded using the Kellgren-Lawrence classification through the posterior-anterior knee X-rays. The concentrations of the inflammatory cytokines and chemokines in plasma were quantified using Luminex microbead-based suspension array (SA) and were cross-validated by enzyme-linked immunosorbent assay (ELISA).

RESULTS

CCL3 in plasma showed the highest ability to discriminate pre-X-KD patients from the controls with an AUC of 0.799. At a cutoff value of 0.168 pg/ml, the sensitivity was 70.21%, the specificity was 96.00%, the positive predictive value was 91.67% and the negative predictive value was 83.72%. As to define disease burden, the plasma levels of resistin, IL6, IL8, CCL3 and CCL4 showed significant association with the severity of X-rays defined knee OA, with regard to the KL classification. Moreover, significant elevation of IL6, IL8, CCL3 and CCL4 levels in plasma were observed in severe knee OA patients (KL grade IV) compared with those with pre-X-KD (KL grade 0-I).

CONCLUSION

We firstly showed that the plasma CCL3 could be potential serum biomarker for knee OA with the capacity to detect pre-X-rays defined changes and stage the severity of damage in knee.

T Cell Migration in Rheumatoid Arthritis

Rheumatoid arthritis (RA) is an autoimmune disease characterized by chronic inflammation in joints, associated with synovial hyperplasia and with bone and cartilage destruction. Although the primacy of T cell-related events early in the disease continues to be debated, there is strong evidence that autoantigen recognition by specific T cells is crucial to the pathophysiology of rheumatoid synovitis. In addition, T cells are key components of the immune cell infiltrate detected in the joints of RA patients. Initial analysis of the cytokines released into the synovial membrane showed an imbalance, with a predominance of proinflammatory mediators, indicating a deleterious effect of Th1 T cells. There is nonetheless evidence that Th17 cells also play an important role in RA. T cells migrate from the bloodstream to the synovial tissue via their interactions with the endothelial cells that line synovial postcapillary venules. At this stage, selectins, integrins, and chemokines have a central role in blood cell invasion of synovial tissue, and therefore in the intensity of the inflammatory response. In this review, we will focus on the mechanisms involved in T cell attraction to the joint, the proteins involved in their extravasation from blood vessels, and the signaling pathways activated. Knowledge of these processes will lead to a better understanding of the mechanism by which the systemic immune response causes local joint disorders and will help to provide a molecular basis for therapeutic strategies.

Macrophage Inflammatory Protein-1 Alpha (MIP-1 alpha)/CCL3: As a Biomarker

Macrophage inflammatory protein-1 alpha (MIP-1α/CCL3) is a chemotactic chemokine secreted by macrophages. It performs various biological functions, such as recruiting inflammatory cells, wound healing, inhibition of stem cells, and maintaining effector immune response. It activates bone resorption cells and directly induces bone destruction. Cells that secrete MIP-1α/CCL3 are increased at sites of inflammation and bone resorption. MIP-1α/CCL3 plays an important role in the pathogenesis of various inflammatory diseases and conditions that exhibit bone resorption, such as periodontitis, multiple myeloma, Sjögren syndrome, and rheumatoid arthritis. Biological fluids from patients with these diseases exhibit elevated levels of MIP-1α/CCL3. This finding indicates that MIP-1\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ \alpha $$\end{document}α/CCL3 protein may have diagnostic potential for the detection of several inflammatory diseases and conditions. This chapter discusses the biological functions of MIP-1α/CCL3; describes several diseases associated with MIP-1α/CCL3, particularly periodontitis; and delineates the potential application of MIP-1α/CCL3 as a biomarker.

Inhibiting histone deacetylase 1 suppresses both inflammation and bone loss in arthritis

OBJECTIVE

Histone deacetylase 1 (HDAC1) is highly expressed in the synovium of RA patients. Thus we aimed to investigate a novel HDAC inhibitor (HDACi), NW-21, designed to target HDAC1. The effect of NW-21 on osteoclast formation and activity, cytokine and chemokine expression in vitro and arthritis in mice was assessed.

METHODS

The effects on human osteoclast formation and activity derived from human blood monocytes stimulated with receptor activator of nuclear factor κB ligand (RANKL) and M-CSF were assessed. The anti-inflammatory activity of NW-21 was assessed using human monocytes stimulated with either TNF-α or lipopolysaccharide for 24 h. mRNA expression of monocyte chemotactic protein 1 (MCP-1), TNF-α, macrophage inflammatory protein 1α (MIP-1α), IL-1 and RANTES (regulated on activation, normal T cell expressed and secreted) was assessed. The effect of NW-21 in the collagen antibody-induced arthritis model was assessed following daily oral administration at 5 mg/kg/day. The HDAC1 inhibitors NW-21 and MS-275 were compared with a broad-acting HDACi, 1179.4b. Effects on inflammation and bone were assessed using paw inflammation scoring, histology and live animal micro-CT.

RESULTS

NW-21 suppressed osteoclast formation and activity as well as significantly reducing mRNA expression of MCP-1 and MIP-1α in monocytes stimulated by lipopolysaccharide or TNF-α (P < 0.05) in vitro. Only inhibitors that targeted HDAC1 (NW-21 and MS-275) reduced inflammation and bone loss in the arthritis model.

CONCLUSION

The results indicate that inhibitors targeting HDAC1, such as NW-21 and MS-275, may be useful for treating RA, as such drugs can simultaneously target both inflammation and bone resorption.

Palmitoylethanolamide and luteolin ameliorate development of arthritis caused by injection of collagen type II in mice

Introduction

N-palmitoylethanolamine (PEA) is an endogenous fatty acid amide belonging to the family of the N-acylethanolamines (NAEs). Recently, several studies demonstrated that PEA is an important analgesic, antiinflammatory, and neuroprotective mediator. The aim of this study was to investigate the effect of co-ultramicronized PEA + luteolin formulation on the modulation of the inflammatory response in mice subjected to collagen-induced arthritis (CIA).

Methods

CIA was induced by an intradermally injection of 100 μl of the emulsion (containing 100 μg of bovine type II collagen (CII)) and complete Freund adjuvant (CFA) at the base of the tail. On day 21, a second injection of CII in CFA was administered. Mice subjected to CIA were administered PEA (10 mg/kg 10% ethanol, intraperitoneally (i.p.)) or co-ultramicronized PEA + luteolin (1 mg/kg, i.p.) every 24 hours, starting from day 25 to 35.

Results

Mice developed erosive hind-paw arthritis when immunized with CII in CFA. Macroscopic clinical evidence of CIA first appeared as periarticular erythema and edema in the hindpaws. The incidence of CIA was 100% by day 28 in the CII-challenged mice, and the severity of CIA progressed over a 35-day period with a resorption of bone. The histopathology of CIA included erosion of the cartilage at the joint. Treatment with PEA or PEA + luteolin ameliorated the clinical signs at days 26 to 35 and improved histologic status in the joint and paw. The degree of oxidative and nitrosative damage was significantly reduced in PEA + luteolin-treated mice, as indicated by nitrotyrosine and malondialdehyde (MDA) levels. Plasma levels of the proinflammatory cytokines and chemokines were significantly reduced by PEA + luteolin treatment.

Conclusions

We demonstrated that PEA co-ultramicronized with luteolin exerts an antiinflammatory effect during chronic inflammation and ameliorates CIA.

Homing of mesenchymal stem cells: mechanistic or stochastic? Implications for targeted delivery in arthritis

Mesenchymal stem cells (MSCs) are multipotent cells with the capacity to undergo chondrogenic differentiation. Systemically administered MSCs have been shown to preferentially accumulate at sites of tissue damage and inflammation, thus MSC-based therapy holds great promise for the treatment of inflammatory diseases such as RA. Modulation of MSC homing may allow targeted delivery of systemically administered MSCs to damaged articular cartilage, where they can suppress immune-mediated cartilage destruction and contribute to cartilage repair via a combination of chondrogenic differentiation and paracrine stimulation of intrinsic residual repair. To harness the potential of MSC homing, a thorough understanding of the mechanism is key. This review discusses current knowledge of the mechanism of MSC homing to injured/inflamed tissue and its implications for targeted MSC-based therapy in arthritis.

Involvement of CD161+ Vδ1+ γδ T cells in systemic sclerosis: association with interstitial pneumonia

OBJECTIVE

Interstitial pneumonia (IP) is a chronic progressive interstitial lung disease associated with high mortality and poor prognosis. However, the pathogenesis of IP remains to be elucidated. The aim of this study was to clarify the role of CD161(+) Vδ1(+) γδ T cells in SSc patients with IP.

METHODS

The proportion of CD161(+) Vδ1(+) γδ T cells in peripheral blood mononuclear cells (PBMCs) and serum sialylated carbohydrate antigen (KL-6) levels were determined. GeneChip analysis was performed with CD161(-) and CD161(+) Vδ1(+) γδ T cells. Cytokine and chemokine expression from CD161(+) Vδ1(+) γδ T cells was measured and used to evaluate the effect of culture supernatant on fibroblast proliferation.

RESULTS

The proportion of CD161(+) Vδ1(+) γδ T cells was significantly higher in SSc than healthy controls (HCs) and correlated negatively with serum KL-6 levels in IP-positive SSc patients. The gene and mRNA expression level of chemokine ligand 3 (CCL3) was markedly higher in CD161(+) Vδ1(+) γδ T cells than in CD161(-) Vδ1(+) γδ T cells. CD161(+) Vδ1(+) γδ T cells in IP-positive SSc patients showed higher production of CCL3 and lower production of IFN-γ than in HCs. Culture supernatant derived from IP-negative and IP-positive SSc patients promoted fibroblast proliferation, whereas that from HCs did not.

CONCLUSION

The small proportion and the altered cell functions of CD161(+) Vδ1(+) γδ T cells among PBMCs in SSc patients play a role in the pathogenesis of IP. These findings suggest that CD161(+) Vδ1(+) γδ T cells may play a regulatory role in the pathogenesis of IP in SSc patients via IFN-γ production.

Targeting angiogenic pathway for chemoprevention of experimental colon cancer using C-phycocyanin as cyclooxygenase-2 inhibitor

An angiogenic pathway was studied that involved stromal tissue degradation with matrix metalloproteinases (MMPs), vesicular endothelial growth factor-A (VEGF-A), and hypoxia inducible factor-1α (HIF-1α) mediated growth regulation in a complex interaction with chemokines, such as monocyte chemoattractant protein-1 (MCP-1) and macrophage inflammatory protein-1β (MIP-1β). Gene and protein expression was studied with real-time PCR, Western immunoblot, and immunofluorescence. Morphological and histopathological analysis of tumor was done, as also the activity of MMPs and HIF-1α by gelatin zymography and ELISA. Binding interactions of proteins were studied by molecular docking. Piroxicam, a traditional NSAID and C-phycocyanin, a biliprotein from Spirulina platensis, were utilized in the chemoprevention of DMH-induced rat colon cancer. A significant number of tumors was evident in DMH treated animals, while with piroxicam and C-phycocyanin, the number and size of tumors/lesions were reduced. Colonic tissues showed severe dysplasia, tubular adenoma, and adenocarcinoma from DMH, with invasive features along with signet ring cell carcinoma. No occurrence of carcinoma was detected in either of the drug treatments or in a combination regimen. An elevated VEGF-A, MMP-2, and MMP-9 level was observed, which is required for metastasis and invasion into surrounding tissues. Drugs induced chemoprevention by down-regulating these proteins. Piroxicam docked in VEGF-A binding site of VEGF-A receptors i.e., VEGFR1 and VEGFR2, while phycocyanobilin (a chromophore of C-phycocyanin) docked with VEGFR1 alone. HIF-1α is up-regulated which is associated with increased oxygen demand and angiogenesis. MCP-1 and MIP-1β expression was also found altered in DMH and regulated by the drugs. Anti-angiogenic role of piroxicam and C-phycocyanin is well demonstrated.

Immune mediators of chronic pelvic pain syndrome

The cause of chronic pelvic pain syndrome (CPPS) has yet to be established. Since the late 1980s, cytokine, chemokine, and immunological classification studies using human samples have focused on identifying biomarkers for CPPS, but no diagnostically beneficial biomarkers have been identified, and these studies have done little to deepen our understanding of the mechanisms underlying chronic prostatic pain. Given the large number of men thought to be affected by this condition and the ineffective nature of current treatments, there is a pressing need to elucidate these mechanisms. Prostatitis types IIIa and IIIb are classified according to the presence of pain without concurrent presence of bacteria; however, it is becoming more evident that, although levels of bacteria are not directly associated with levels of pain, the presence of bacteria might act as the initiating factor that drives primary activation of mast-cell-mediated inflammation in the prostate. Mast cell activation is also known to suppress regulatory T cell (Treg) control of self-tolerance and also activate neural sensitization. This combination of established autoimmunity coupled with peripheral and central neural sensitization can result in the development of multiple symptoms, including pelvic pain and bladder irritation. Identifying these mechanisms as central mediators in CPPS offers new insight into the prospective treatment of the disease.

The macrophage inflammatory proteins MIP1α (CCL3) and MIP2α (CXCL2) in implant-associated osteomyelitis: linking inflammation to bone degradation

Bacterial infections of bones remain a serious complication of endoprosthetic surgery. These infections are difficult to treat, because many bacterial species form biofilms on implants, which are relatively resistant towards antibiotics. Bacterial biofilms elicit a progressive local inflammatory response, resulting in tissue damage and bone degradation. In the majority of patients, replacement of the prosthesis is required. To address the question of how the local inflammatory response is linked to bone degradation, tissue samples were taken during surgery and gene expression of the macrophage inflammatory proteins MIP1α (CCL3) and MIP2α (CXCL2) was assessed by quantitative RT-PCR. MIPs were expressed predominantly at osteolytic sites, in close correlation with CD14 which was used as marker for monocytes/macrophages. Colocalisation of MIPs with monocytic cells could be confirmed by histology. In vitro experiments revealed that, aside from monocytic cells, also osteoblasts were capable of MIP production when stimulated with bacteria; moreover, CCL3 induced the differentiation of monocytes to osteoclasts. In conclusion, the multifunctional chemokines CCL3 and CXCL2 are produced locally in response to bacterial infection of bones. In addition to their well described chemokine activity, these cytokines can induce generation of bone resorbing osteoclasts, thus providing a link between bacterial infection and osteolysis.

NK cell intrinsic regulation of MIP-1α by granzyme M

Granzymes are generally recognized for their capacity to induce various pathways of perforin-dependent target cell death. Within this serine protease family, Granzyme M (GrzM) is unique owing to its preferential expression in innate effectors such as natural killer (NK) cells. During Listeria monocytogenes infection, we observed markedly reduced secretion of macrophage inflammatory protein-1 alpha (MIP-1α) in livers of GrzM-deficient mice, which resulted in significantly impaired NK cell recruitment. Direct stimulation with IL-12 and IL-15 demonstrated that GrzM was required for maximal secretion of active MIP-1α. This effect was not due to reduced protein induction but resulted from heightened intracellular accumulation of MIP-1α, with reduced release. These results demonstrate that GrzM is a critical mediator of innate immunity that can regulate chemotactic networks and has an important role in the initiation of immune responses and pathogen control.