scholarly journals TNF is a homoeostatic regulator of distinct epigenetically primed human osteoclast precursors

2021 ◽  
pp. annrheumdis-2020-219262
Author(s):  
Cecilia Ansalone ◽  
John Cole ◽  
Sabarinadh Chilaka ◽  
Flavia Sunzini ◽  
Shatakshi Sood ◽  
...  
Keyword(s):  
Epigenetic Modification ◽  
Human Peripheral Blood ◽  
Joint Destruction ◽  
Receptor Expression ◽  
Skeletal Health ◽  
Flow Cytometric ◽  
Human Osteoclast ◽  
The Relationship ◽  
Pathological Consequence ◽  
Necrosis Factor

ObjectivesCirculating myeloid precursors are responsible for post-natal osteoclast (OC) differentiation and skeletal health, although the exact human precursors have not been defined. Enhanced osteoclastogenesis contributes to joint destruction in rheumatoid arthritis (RA) and tumour necrosis factor (TNF) is a well-known pro-osteoclastogenic factor. Herein, we investigated the interplay between receptor activator of nuclear factor kappa-Β ligand (RANK-L), indispensable for fusion of myeloid precursors and the normal development of OCs, and TNF in directing the differentiation of diverse pre-OC populations derived from human peripheral blood.MethodsFlow cytometric cell sorting and analysis was used to assess the potential of myeloid populations to differentiate into OCs. Transcriptomic, epigenetic analysis, receptor expression and inhibitor experiments were used to unravel RANK-L and TNF signalling hierarchy.ResultsTNF can act as a critical homoeostatic regulator of CD14+ monocyte (MO) differentiation into OCs by inhibiting osteoclastogenesis to favour macrophage development. In contrast, a distinct previously unidentified CD14−CD16−CD11c+ myeloid pre-OC population was exempt from this negative regulation. In healthy CD14+ MOs, TNF drove epigenetic modification of the RANK promoter via a TNFR1-IKKβ-dependent pathway and halted osteoclastogenesis. In a subset of patients with RA, CD14+ MOs exhibited an altered epigenetic state that resulted in dysregulated TNF-mediated OC homoeostasis.ConclusionsThese findings fundamentally re-define the relationship between RANK-L and TNF. Moreover, they have identified a novel pool of human circulating non-MO OC precursors that unlike MOs are epigenetically preconditioned to ignore TNF-mediated signalling. In RA, this epigenetic preconditioning occurs in the MO compartment providing a pathological consequence of failure of this pathway.

scholarly journals Essential Role for the C5a Receptor in Regulating the Effector Phase of Synovial Infiltration and Joint Destruction in Experimental Arthritis

2002 ◽  
Vol 196 (11) ◽  
pp. 1461-1471 ◽  
Author(s):  
Ethan P. Grant ◽  
Dominic Picarella ◽  
Timothy Burwell ◽  
Tracy Delaney ◽  
Alisa Croci ◽  
...  
Keyword(s):  
Synovial Fluid ◽  
Joint Destruction ◽  
Inflammatory Cells ◽  
Receptor Expression ◽  
C5a Receptor ◽  
Genetic Ablation ◽  
Proinflammatory Mediators ◽  
Related Family ◽  
Factor Α ◽  
Necrosis Factor

A characteristic feature of rheumatoid arthritis is the abundance of inflammatory cells in the diseased joint. Two major components of this infiltrate are neutrophils in the synovial fluid and macrophages in the synovial tissue. These cells produce cytokines including tumor necrosis factor α and other proinflammatory mediators that likely drive the disease through its effector phases. To investigate what mechanisms underlie the recruitment of these cells into the synovial fluid and tissue, we performed expression analyses of chemoattractant receptors in a related family that includes the anaphylatoxin receptors and the formyl-MetLeuPhe receptor. We then examined the effect of targeted disruption of two abundantly expressed chemoattractant receptors, the receptors for C3a and C5a, on arthritogenesis in a mouse model of disease. We report that genetic ablation of C5a receptor expression completely protects mice from arthritis.

Plasma Level of IL-1β in Disseminated Intravascular Goagulation

1991 ◽  
Vol 65 (04) ◽  
pp. 364-368 ◽  
Author(s):  
Hideo Wada ◽  
Shigehisa Tamaki ◽  
Motoaki Tanigawa ◽  
Mikio Takagi ◽  
Yoshitaka Mori ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Tumor Necrosis Factor ◽  
Plasma Level ◽  
Organ Failure ◽  
Tumor Necrosis ◽  
Mononuclear Cells ◽  
Solid Cancer ◽  
Normal Individuals ◽  
The Relationship ◽  
Necrosis Factor

SummaryThe plasma level of interleukin-1β (IL-1β) was determined in normal individuals, patients with disseminated intravascular coagulation (DIC), patients in the pre-DIC period (within 7 days before the onset of DIC), and non-DIC patients to examine the relationship between DIC and the plasma ILlp level. The plasma IL-1β level was 0-0.085 ng/ml in normal individuals, with little difference being seen according to related age. It was significantly higher in the DIC group (0.19 ± 0.19 ng/ml) than in the pre-DIC group (0.05 ± 0.08 ng/ml) or the non-DIC group (0.09 ± 0.01 ng/ml). The plasma IL-1β level was not markedly elevated in leukemia patients, even in the DIC group, but it was significantly increased in the DIC group of solid cancer patients and was generally elevated in patients with sepsis. It was markedly elevated to 0.39 ± 0.26 ng/ml in patients with organ failure. When mononuclear cells were incubated with lipopolysaccharide, it was found that IL-1β, tumor necrosis factor, and tissue factor (TF) were released into the medium, and there was an increase of TF release from endothelial cells incubated with this medium. These results suggest that the increase in IL-Iβ reflected the activation of monocytes and may be an important factor in DIC and its associated organ failure.

scholarly journals Lipopolysaccharides promote pulmonary fibrosis in silicosis through the aggravation of apoptosis and inflammation in alveolar macrophages

2020 ◽  
Vol 15 (1) ◽  
pp. 598-605
Author(s):  
Shiyi Tan ◽  
Shang Yang ◽  
Mingke Chen ◽  
Yurun Wang ◽  
Li Zhu ◽  
...  
Keyword(s):  
Pulmonary Fibrosis ◽  
Alveolar Macrophages ◽  
Inflammatory Factors ◽  
Necrosis Factor Alpha ◽  
Defensive Role ◽  
Factor Alpha ◽  
Apoptosis And Inflammation ◽  
The Relationship ◽  
Lps Treatment ◽  
Necrosis Factor

AbstractAlveolar macrophages (AMs) play an important defensive role by removing dust and bacteria from alveoli. Apoptosis of AMs is associated with lung fibrosis; however, the relationship between this apoptotic event and environmental factors, such as the presence of lipopolysaccharides (LPSs) in the workplace, has not yet been addressed. To investigate whether exposure to LPS can exacerbate fibrosis, we collected AMs from 12 male workers exposed to silica and incubated them in the presence and absence of LPS for 24 h. We show that the levels of cleaved caspase-3 and pro-inflammatory cytokines interleukin (IL)-1β, IL-6, and tumor necrosis factor-alpha were increased in these AMs following LPS treatment. Moreover, we demonstrate that LPS exposure aggravated apoptosis and the release of inflammatory factors in AMs in a mouse model of silicosis, which eventually promoted pulmonary fibrosis. These results suggest that exposure to LPS may accelerate the progression of pulmonary fibrosis in silicosis by increasing apoptosis and inflammation in AMs.

Tumor necrosis factor-α inhibitors alleviation of experimentally induced neuropathic pain is associated with modulation of TNF receptor expression

2014 ◽  
Vol 92 (11) ◽  
pp. 1490-1498 ◽  
Author(s):  
Pablo Andrade ◽  
Govert Hoogland ◽  
John S. Del Rosario ◽  
Harry W. Steinbusch ◽  
Veerle Visser-Vandewalle ◽  
...  
Keyword(s):  
Neuropathic Pain ◽  
Tumor Necrosis Factor ◽  
Tumor Necrosis ◽  
Tumor Necrosis Factor Α ◽  
Receptor Expression ◽  
Tnf Receptor ◽  
Factor Α ◽  
Necrosis Factor ◽  
Experimentally Induced

scholarly journals Regulation of interleukin 6 receptor expression in human monocytes and monocyte-derived macrophages. Comparison with the expression in human hepatocytes.

1989 ◽  
Vol 170 (5) ◽  
pp. 1537-1549 ◽  
Author(s):  
J Bauer ◽  
T M Bauer ◽  
T Kalb ◽  
T Taga ◽  
G Lengyel ◽  
...  
Keyword(s):  
Plasma Cells ◽  
Human Peripheral Blood ◽  
Receptor Expression ◽  
Mrna Levels ◽  
Blood Monocytes ◽  
Inflammatory Conditions ◽  
High Concentrations ◽  
Human Primary Hepatocytes ◽  
Stimulation Of

IL-6 is a cytokine with pleiotropic biological functions, including induction of the hepatic acute phase response and differentiation of activated B cells into Ig-secreting plasma cells. We found that human peripheral blood monocytes express the IL-6-R, which is undetectable on the large majority of lymphocytes of healthy individuals. Stimulation of monocytes by endotoxin or IL-1 causes a rapid downregulation of IL-6-R mRNA levels and a concomitant enhancement of IL-6 mRNA expression. IL-6 itself was found to suppress the IL-6-R at high concentrations. A gradual decrease of IL-6-R mRNA levels was observed along in vitro maturation of monocytes into macrophages. We show that downregulation of IL-6-R mRNA levels by IL-1 and IL-6 is monocyte specific, since IL-6-R expression is stimulated by both IL-1 and IL-6 in cultured human primary hepatocytes. Our data indicate that under noninflammatory conditions, monocytes may play a role in binding of trace amounts of circulating IL-6. Repression of monocytic IL-6-R and stimulation of hepatocytic IL-6-R synthesis may represent a shift of the IL-6 tissue targets under inflammatory conditions.

scholarly journals Formation of Autoimmune Lesions Is Independent of Antibiotic Treatment in NOD Mice

2021 ◽  
Vol 22 (6) ◽  
pp. 3239
Author(s):  
 Mami Sato ◽  
Rieko Arakaki ◽  
Hiroaki Tawara ◽  
Takaaki Tsunematsu ◽  
Naozumi Ishimaru
Keyword(s):  
Intestinal Microbiota ◽  
Flow Cytometric Analysis ◽  
Nod Mice ◽  
Antibiotic Administration ◽  
T And B Cells ◽  
Spleen Cells ◽  
Flow Cytometric ◽  
Enteral Microbiota ◽  
The Relationship

The relationship between autoimmunity and changes in intestinal microbiota is not yet fully understood. In this study, the role of intestinal microbiota in the onset and progression of autoimmune lesions in non-obese diabetic (NOD) mice was evaluated by administering antibiotics to alter their intestinal microenvironment. Flow cytometric analysis of spleen cells showed that antibiotic administration did not change the proportion or number of T and B cells in NOD mice, and pathological analysis demonstrated that autoimmune lesions in the salivary glands and in the pancreas were also not affected by antibiotic administration. These results suggest that the onset and progression of autoimmunity may be independent of enteral microbiota changes. Our findings may be useful for determining the appropriate use of antibiotics in patients with autoimmune diseases who are prescribed drugs to maintain systemic immune function.

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