scholarly journals Absence of Fms-like tyrosine kinase 3 ligand (Flt3L) signalling protects against collagen-induced arthritis

2013 ◽  
Vol 74 (1) ◽  
pp. 211-219 ◽  
Author(s):  
M I P Ramos ◽  
O N Karpus ◽  
P Broekstra ◽  
S Aarrass ◽  
S E Jacobsen ◽  
...  

ObjectiveComprehending the mechanisms that regulate activation of autoreactive T cells and B cell antibody production is fundamental for understanding the breakdown in self-tolerance and development of autoimmunity. Here we studied the role of Fms-like tyrosine kinase 3 ligand (Flt3L) signalling in the pathogenesis of collagen-induced arthritis (CIA).MethodsCIA was induced in mice lacking Flt3L (Flt3L−/−)and wild-type (WT) littermates (C57/BL6, 8–10 weeks old). Mice were killed in the initial phase (acute phase: experiment 1) and late phase (chronic phase: experiment 2) of the disease. Arthritis severity was assessed using a semiquantitative scoring system (0–4), and histological analysis of cellular infiltration, cartilage destruction and peptidoglycan loss was performed. Phenotypic and functional analysis of T and B cells, FoxP3 expression, activation and lymphocyte costimulatory markers, and cytokine production were performed ex vivo by flow cytometry in lymph nodes. Serum collagen type II (CII)-specific antibodies were measured by ELISA.ResultsFlt3L−/−mice showed a marked decrease in clinical arthritis scores and incidence of arthritis in both acute and chronic phases of CIA compared with WT mice. Moreover, decreased synovial inflammation and joint destruction was observed. Both the magnitude and quality of T cell responses were altered in Flt3L−/−. In the acute phase, the amount of CII-specific IgG2a antibodies was lower in Flt3L−/−than WT mice.ConclusionsThese results strongly suggest a role for Flt3L signalling in the development of arthritis.

2020 ◽  
Author(s):  
Seon Uk Kim ◽  
Hyun Jung Yoo ◽  
Jung Ho Kim ◽  
Hae Jun Hwang ◽  
Jin Kyun Park ◽  
...  

Abstract Background/PurposeRheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease characterized by bone and cartilage destruction with leukocyte infiltration and activation at synovial tissue. The fibroblast-like synoviocytes (FLS) have a central role in disease pathogenesis and their invasiveness correlates with articular damage in RA patients. Spleen tyrosine kinase (SYK) is a non-receptor tyrosine kinase known to have a crucial role in immune receptor signaling. This study aimed to evaluate the inhibitory effect of a novel small-molecule SYK inhibitor, SKI-O-592, on the invasiveness of RA FLS and inflammation of monocytes in vitro and in a mouse collagen-induced arthritis (CIA) model in vivo.MethodsFLS were isolated from synovial tissues of RA patients. FLS were treated with SKI-O-592 for 1 hr and then stimulated with tumor necrosis factor-alpha (TNF-α) for 48 hr. After stimulation, cell viability was measured using cell counting kit-8 (CCK-8) assay. The levels of IL-6, IL-8, CXCL10, MMP-3, and TNF-α were measured in culture supernatant of RA FLS and the monocytic cell line THP-1 cells by ELISA. Wound healing assay transwell migration and invasion assay using RA FLS was performed to evaluate cell migration ability. The adhesion ability of FLS was evaluated by co-culture with calcein-AM labeled THP-1 cells, and the expression of VCAM-1, ICAM-1, α-tubulin, β-actin, total and phosphorylated SYK, c-Jun N-terminal kinase (JNK), p38, ERK, phosphorylated c-Jun, mitogen-activated protein kinase kinase 4 (MKK4), and MKK3/6 was determined by Western blotting. CIA was developed in DBA/1J mice. Clinical arthritis score and histological scores were evaluated after treatment with SKI-O-592.ResultsSKI-O-592 reduced the secretion of chemokine, CXCL10 in RA FLS. Migration of cells to the wound region and through membrane pores and matrigel were decreased by SKI-O-592. Phosphorylation of JNK and p38 was reduced by SKI-O-592 after TNF-α stimulation. SKI-O-592 decreased secretion of TNF-α levels dose-dependently in THP-1 cells with IgG stimulation. The viability and proliferation of FLS and THP-1 were not affected by SKI-O-592. In the CIA model, scores for clinical arthritis and histology were decreased following SKI-O-592 treatment.ConclusionSKI-O-592 inhibited the invasiveness of RA FLS and had an anti-inflammatory effect on monocytes. SKI-O-592 exhibited therapeutic effects in the mouse CIA model by improving clinical and histological scores with amelioration of joint destruction. In conclusion, a novel SYK inhibitor, SKI-O-592, may provide a new therapeutic option for RA patients.


Cells ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1537
Author(s):  
Milos Pekny ◽  
Ulrika Wilhelmsson ◽  
Anna Stokowska ◽  
Turgut Tatlisumak ◽  
Katarina Jood ◽  
...  

Increased sensitivity of methods assessing the levels of neurofilament light chain (NfL), a neuron-specific intermediate filament protein, in human plasma or serum, has in recent years led to a number of studies addressing the utility of monitoring NfL in the blood of stroke patients. In this review, we discuss that elevated blood NfL levels after stroke may reflect several different neurobiological processes. In the acute and post-acute phase after stroke, high blood levels of NfL are associated with poor clinical outcome, and later on, the blood levels of NfL positively correlate with secondary neurodegeneration as assessed by MRI. Interestingly, increased blood levels of NfL in individuals who survived stroke for more than 10 months were shown to predict functional improvement in the late phase after stroke. Whereas in the acute phase after stroke the injured axons are assumed to be the main source of blood NfL, synaptic turnover and secondary neurodegeneration could be major contributors to blood NfL levels in the late phase after stroke. Elevated blood NfL levels after stroke should therefore be interpreted with caution. More studies addressing the clinical utility of blood NfL assessment in stroke patients are needed before the inclusion of NfL in the clinical workout as a useful biomarker in both the acute and the chronic phase after stroke.


2021 ◽  
Author(s):  
Jin-Sil Park ◽  
Donghyun Lee ◽  
SeungCheon Yang ◽  
Hyun Sik Na ◽  
Keun-Hyung Cho ◽  
...  

Abstract Background: Rheumatoid arthritis (RA) is a progressive systemic autoimmune disease that is characterized by infiltration of inflammatory cells into the hyperplastic synovial tissue, resulting in subsequent destruction of adjacent articular cartilage and bone. Methotrexate (MTX), the first conventional disease-modifying antirheumatic drug (DMARD), could alleviate articular damage in RA and is implicated in humoral and cellular immune responses. However, MTX has several side effects, so efficient delivery of low-dose MTX is important. Methods: To investigate the efficacy of MTX-loaded nanoparticles (MTX-NPs) against RA, free MTX or MTX-NPs were administered as subcutaneous route to mice with collagen-induced arthritis (CIA) at 3 weeks after CII immunization. The levels of inflammatory factors in tissues were determined by immunohistochemistry, confocal microscopy, real-time PCR, and flow cytometry. Results: MTX-NPs ameliorated arthritic severity and joint destruction in collagen-induced arthritis (CIA) mice compared to free MTX-treated CIA mice. The levels of inflammatory cytokines, including interleukin (IL)-1β, tumor necrosis factor-α, and vascular endothelial growth factor, were reduced in MTX-NPs-treated mice. Numbers of phosphorylated STAT3-positive CD4+ cells and CD4+IL-17+ cells were reduced whereas the number of CD4+CD25+Foxp3+ cells increased in spleens from MTX- NPs-treated CIA mice compared to MTX-treated CIA mice. The frequency of CD19+CD25+Foxp3+ regulatory B cells increased in ex vivo splenocytes from MTX-loaded NPs-treated CIA mice compared to MTX-treated CIA mice. Conclusion: The results suggest that MTX-loaded NPs have therapeutic potential for RA.


2006 ◽  
Vol 74 (9) ◽  
pp. 5227-5235 ◽  
Author(s):  
Hongyan Xiao ◽  
Javed Siddiqui ◽  
Daniel G. Remick

ABSTRACTA recent hypothesis postulates that sepsis moves through different phases, with periods of enhanced inflammation alternating with periods of immune suppression. In this study we determined the levels of inflammation present during early and late septic deaths to examine whether death was due to hyperinflammation or immunosuppression. The murine model of sepsis induced by cecal ligation and puncture (CLP) was used. Complete blood counts, plasma interleukin-6 (IL-6) levels, and body weights were determined. Mice that died within the first 4 days had increased plasma levels of IL-6, indicating that there was activation of the immune system. Cecal resection on day 4 after CLP resulted in decreased abscess size, lower circulating neutrophil counts, decreased anemia, and improved survival compared to the results for mice that received only antibiotic and fluid therapy. All of the mice that died in the chronic phase of infection (after day 4) had positive peritoneal cultures containing significantly more bacteria than the cultures for surviving mice. After day 4, none of the surviving mice exhibited increases in the plasma levels of IL-6. Dying mice exhibited mixed IL-6 responses; for 41% of the mice there was never an increase in the IL-6 levels in the chronic phase, while for other mice the levels of IL-6 transiently increased prior to death. Peritoneal macrophages were obtained in the late phase of sepsis from moribund and healthy mice and were stimulated ex vivo. The cells from the moribund mice produced significantly less IL-6 than the cells obtained from healthy mice produced. These results indicate that in mice that die in the early phase there is uniformly increased inflammation. However, during the chronic phase of sepsis, some mice die with evidence of immunosuppression (increased bacterial growth and low IL-6 levels), while other mice die with immunostimulation (high IL-6 levels and bacterial growth). Determining the inflammatory status of individual patients may help guide appropriate, targeted therapy.


2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 934.3-934
Author(s):  
M. Kim ◽  
Y. Choe ◽  
H. Lee ◽  
Y. H. Cheon ◽  
S. I. Lee

Background:Histamine-releasing factor/translationally controlled tumor protein (HRF/TCTP) stimulates cancer progression and allergic responses. Increased expression of HRF/TCTP occurs in joints of rheumatoid arthritis (RA) patients, but the role of HRF/TCTP in RA remains undefinedObjectives:In this study, we explored the pathogenic significance of HRF/TCTP and evaluated therapeutic effects of HRF/TCTP blockade in RA.Methods:HRF/TCTP transgenic (TG) and knockdown (KD) mice with collagen-induced arthritis (CIA) were used to determine experimental phenotypes of RA. HRF/TCTP levels were measured in sera and joint fluids in patients with RA and compared to those with osteoarthritis, ankylosing spondylitis, Behcet disease, and healthy controls. HRF/TCTP expression was also assessed in synovium and fibroblast-like synoviocytes (FLS) obtained from RA or OA patients. Finally, we assessed effects of HRF/TCTP and dimerized HRF/TCTP binding peptide-2 (dTBP2), an inhibitor of HRF/TCTP, in RA-FLS and CIA mice.Results:Our clinical, radiological, histological, and biochemical analyses indicate that inflammatory responses and joint destruction were increased in HRF/TCTP TG mice, and decreased in KD mice compared to wild-type littermates. HRF/TCTP levels were higher in sera, synovial fluid, synovium, and FLS of patients with RA than in control groups. Serum levels of HRF/TCTP correlated well with disease activity in RA. Tumor-like aggressiveness of RA-FLS was exacerbated by HRF/TCTP stimulation and ameliorated by dTBP2 treatment. dTBP2 exerted protective and therapeutic effects in CIA mice, and had no detrimental effect in a murine tuberculosis model.Conclusion:Our results indicate that HRF/TCTP represents a novel biomarker and therapeutic target for diagnosis and treatment of RA.References:N/AAcknowledgments :National Research Foundation of KoreaKorea Health Industry Development InstituteDisclosure of Interests:None declared


2021 ◽  
Vol 10 (6) ◽  
pp. 1241
Author(s):  
Yoshiya Tanaka

In rheumatoid arthritis, a representative systemic autoimmune disease, immune abnormality and accompanying persistent synovitis cause bone and cartilage destruction and systemic osteoporosis. Biologics targeting tumor necrosis factor, which plays a central role in the inflammatory process, and Janus kinase inhibitors have been introduced in the treatment of rheumatoid arthritis, making clinical remission a realistic treatment goal. These drugs can prevent structural damage to bone and cartilage. In addition, osteoporosis, caused by factors such as menopause, aging, immobility, and glucocorticoid use, can be treated with bisphosphonates and the anti-receptor activator of the nuclear factor-κB ligand antibody. An imbalance in the immune system in rheumatoid arthritis induces an imbalance in bone metabolism. However, osteoporosis and bone and cartilage destruction occur through totally different mechanisms. Understanding the mechanisms underlying osteoporosis and joint destruction in rheumatoid arthritis leads to improved care and the development of new treatments.


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