Tumor necrosis factor-alpha cooperates with receptor activator of nuclear factor kappaB ligand in generation of osteoclasts in stromal cell-depleted rat bone marrow cell culture

A member of the tumor necrosis factor (TNF) family, receptor activator of nuclear factor kappaB ligand (RANKL; also known as ODF, OPGL, and TRANCE), plays critical roles in osteoclast differentiation and activation in the presence of macrophage colony-stimulating factor (M-CSF). Recently, TNF-alpha has also been shown to induce the formation of multinucleated osteoclast-like cells (MNCs) in the presence of M-CSF from mouse macrophages. We demonstrated that mononuclear preosteoclast-like cells (POCs) were formed in the presence of conditioned medium of osteoblastic cells in a rat bone marrow culture depleted of stromal cells. Using this culture system, in this study we examined whether TNF-alpha affects differentiation into POCs from hematopoietic progenitor cells. Human TNF-alpha (hTNF-alpha) markedly stimulated the formation of POCs. Moreover, a concentration as low as 0.005 ng/mL of hTNF-alpha increased the level of mRNA for calcitonin receptor (CTR) and cathepsin-K of POCs. The POCs induced by hTNF-alpha formed MNCs, which showed dentine-resorbing activity after coculture with primary osteoblasts. Stimulation was observed after 24 h of treatment with hTNF-alpha only on day 1 or day 2 of the culture. After 24 h of hTNF-alpha treatment, expression of the receptor activator of nuclear factor kappaB (RANK) mRNA was markedly increased. The addition of soluble RANKL (sRANKL) to the preformed POCs efficiently induced MNCs. Interestingly, treatment of bone marrow cells with hTNF-alpha and sRANKL synergistically augmented the formation of MNCs. This formation was abolished by the addition of human osteoprotegerin (hOPG). These results suggest that cooperation of TNF-alpha and RANKL is important for osteoclastogenesis.     

Regulation of bone destruction in rheumatoid arthritis through RANKL-RANK pathways

Recent studies have demonstrated that osteoclasts, the primary cells responsible for bone resorption, are mainly involved in bone and joint destruction in rheumatoid arthritis(RA) patients. Recent progress in bone cell biology has revealed the molecular mechanism of osteoclast differentiation and bone resorption by mature osteoclasts. We highlight here the potential role of the receptor activator of nuclear factor κB ligand(RANKL)-RANK pathways in bone destruction in RA and review recent clinical trials treating RA by targeting RANKL.     

Involvement of endogenous interleukin-10 and tumor necrosis factor-alpha in renal ischemia-reperfusion injury

BACKGROUND: Ischemia followed by reperfusion is a common clinical event associated with a pro-inflammatory response leading to organ dysfunction. The aim of the present study is to evaluate the interplay between this pro-inflammatory response and apoptosis. We investigated the role of the pro-inflammatory mediator tumor necrosis factor-alpha (TNF-alpha) and the anti-inflammatory mediator interleukin-10 (IL-10) in inflammation and apoptosis after renal ischemia reperfusion. METHODS: Male Swiss mice were subjected to 45 min of ischemia followed by reperfusion and subsequently administered neutralizing Abs against either TNF-alpha (TN3), IL-10 (JES5-2A5) or control. RESULTS: After 1 day of reperfusion, anti-TNF-alpha treatment reduced whereas anti-IL-10 treatment exacerbated postischemic renal injury, inflammation, and, to a lesser extent, apoptosis as measured by changes in blood urea nitrogen content, immunohistologically detectable renal TNF-alpha protein and neutrophils, histological integrity of renal parenchyma, and DNA ladder formation. Furthermore, anti-IL-10 treatment enhanced major histocompatibility complex class I and II expression at day 7 as measured by enzyme immunoassay and immunohistology. CONCLUSIONS: These data indicate that the extent of reperfusion-induced apoptosis is modulated by the inflammatory response, during which locally produced TNF-alpha plays a significant role in the development of tissue injury. Subsequently, this pro-inflammatory reaction is followed by endogenous production of the anti-inflammatory cytokine IL-10, which serves as a physiological counterbalance to the effects of TNF-alpha. These novel pathophysiological insights may provide new basis for the development of tools for limiting ischemia and reperfusion injury.     

Serum levels and receptor expression of tumor necrosis factor-alpha following human allogeneic and autologous bone marrow transplantation.

We have investigated tumor necrosis factor-alpha levels in serum samples of patients before and after allogenic (16 patients) or autologous (8 patients) bone marrow transplantation. A sensitive immunoradiometric assay for monitoring levels of endogenous tumor necrosis factor-alpha was used. The serum levels of tumor necrosis factor-alpha were found to be relatively low (ranging from less than 15 to 77 pg/ml). Among 13 patients having graft-versus-host disease following allogeneic bone marrow transplantation 8 patients did not have detectable tumor necrosis factor-alpha (less than 15 pg/ml) while 4 out of 8 patients undergoing autologous bone marrow transplantation had detectable tumor necrosis factor-alpha levels (15 pg/ml), indicating a lack of correlation between tumor necrosis factor-alpha serum levels and the occurrence of graft-versus-host disease. Because the tumor necrosis factor-alpha levels detected in patient sera could be regulated by TNF-receptor expression, the presence of TNF-receptor on patients' peripheral blood mononuclear cells was also studied using fluorescent liposome-conjugated tumor necrosis factor-alpha and immunofluorescence analysis. Our data indicate that peripheral blood mononuclear cells of some patients receiving either autologous or allogeneic bone marrow transplantation expressed significant levels of TNF-receptors, suggesting a lack of correlation between TNF-receptor expression and graft-versus-host disease development.     

Multi-omics analysis of biomarkers and molecular mechanism of rheumatoid arthritis with bone destruction

ObjectivesOur study aimed to elucidate the role of metabolites, bacteria, and fungi in rheumatoid arthritis (RA) patients with bone destruction (BD(+)) and identify some biomarkers to predicate bone progression of RA.MethodsPlasma metabolites of the 127 RA patients and 69 healthy controls were conducted by using nontargeted liquid chromatography-mass spectrometry (LC-MS). The gut bacteria and fungi were assessed by 16S rRNA and internal transcribed spacer (ITS).ResultsCompared with RA patients without bone destruction (BD(?)), some metabolites, bacteria, and fungi were altered in BD(+). Seven metabolites were selected as key metabolites for classifying the BD(+) and BD(?) groups with moderate accuracy (AUC = 0.71). Metabolites-groups, metabolites-metabolites, and metabolites-clinical factors had a certain correlation, and 7 metabolites were enriched in glycerophospholipid metabolism and L-arginine and proline metabolism pathways. The bacteria and fungi of the BD(+) group showed significant differences in composition and function compared with BD(?) group. The changed 4 bacteria and 12 fungi yielded accuracy (AUC = 0.74 and AUC = 0.87, respectively) for the two groups. Taking 7 metabolites, 4 bacteria, and 12 fungi as a panel for AUC analysis, an improved AUC of 0.99 significantly discriminated the two groups. The changed metabolites, gut bacteria, and fungi may affect the pathway related to L-arginine.ConclusionsOur nontargeted LC-MS, 16S rRNA, and ITS highlighted a novel link among the metabolites, bacteria, fungi, and pathology of BD(+), which could contribute to our understanding of the role of metabolites, bacteria, and fungi in BD(+) etiology and offered some novel biomarkers to predict the bone progression of RA.     

Mechanisms of joint destruction in rheumatoid arthritis

We review the mechanisms involved in irreversible cartilage damage in inflammatory arthritis, in the context of experimental work carried out by members of the Department of Orthopedics, Yokohama City University School of Medicine, in the author's laboratory. The importance of the superficial layer of cartilage, and the phenotypic differences between superficial and deep chondrocytes with respect to nitric oxide production are emphasized. In addition, we describe some of the consequences resulting from the interaction of nitric oxide and reacting oxygen radicals at the cartilage surface. Received for publication on June 22, 1999     

破骨细胞在类风湿关节炎致骨破坏病理变化中的作用及其调控

类风湿关节炎(RA)是一种严重的慢性自身免疫性炎症性疾病,关节软骨及骨破坏是RA的主要病理变化,是患者致残的主要原因。破骨细胞(OC)在RA骨破坏的病理过程中起关键作用,其调控依赖于OC形成、分化及活化的过程。巨噬细胞、滑膜成纤维细胞等是OC形成的主要来源,促炎性细胞因子在这个过程中起重要作用。主要的是RANK/RANKL/OPG、MCSF、TNF、IL-1和IL-17,这些细胞因子通过不同的信号传导通路促进OC的成熟及分化;此外,有些细胞因子对OC的分化及骨吸收作用产生负性调控作用,如IL-27、IL-4、IL-10、IFN-γ,大部分细胞因子通过RANK/RANKL/OPG系统,直接或间接作用于OC,两者之间的平衡决定骨破坏的结局。这些细胞因子通过多条信号传导通路介导OC对骨破坏的调控作用,其中NFATc1是关键的调节因子,如RANKL通过NF-κB/AP-1/c-fos和钙离子信号通路两条信号通路,调节NFATc1的活化,促进OC分化;TNF通过激活NF-κB,JNK和p38通路,活化NFATc1促进OC形成,还包括MAPK、STAT等通路。深入了解OC的病理过程及骨形成和骨吸收机制,监测及干扰促进OC活化的细胞因子,为早期RA的治疗提供新的靶点。     

Tumor necrosis factor-alpha and tumor necrosis factor receptor I, II levels in patients with severe burns

Tumor necrosis factor alpha (TNF-alpha) and tumor necrosis factor receptor I and II (TNFRI and TNFRII) were studied in 24 burn patients who had a total burn surface area (TBSA) of 50.2 +/- 20.4%. Immediately after the injury, both the TNFRI and TNFRII levels correlated significantly with TBSA (r = 0.7344, P < 0.0001; r = 0.6074, P = 0.0012). The TNFRI and TNFRII levels immediately after the injury were significantly higher in the 11 patients who later died of their burns than in the 13 patients who survived (0.8 +/- 0.4 ng/ml vs. 1.8 +/- 0.7 ng/ml, P = 0.0002; 2.3 +/- 1.1 ng/ml vs. 4.5 +/- 1.6 ng/ml, P = 0.0009). The TNF-alpha levels immediately after the injury did not differ significantly between the group that survived and the group that died. The TNFRI and TNFRII values for the entire follow-up period also correlated significantly with TBSA. Peak TNFRI and TNFRII levels were significantly higher in the group that died than in the group that survived (6.0 +/- 4.7 ng/ml vs. 14.1 +/- 7.8 ng/ml, P = 0.0009; 7.0 +/- 5.1 ng/ml vs. 16.7 +/- 5.2 ng/ml, P = 0.0003). The TNF-alpha levels correlated significantly with both the TNFRI and the TNFRII levels. The TNFRI and TNFRII levels thus closely reflected the severity of the burns in both the acute postburn period and the subsequent follow-up period. In other words, these parameters well reflected the severity and outcome of the burns, irrespective of the presence or absence of accompanying infection.     

Large geodes in rheumatoid arthritis without joint destruction

Although subchondral geodes are a well-known radiological feature of rheumatoid arthritis (RA), large geodes are uncommon. Progressive bone damage with pathological fractures has been reported. We report the case of a 49-year-old man with seropositive RA in whom large, rapidly progressive geodes in the wrists, hands, and feet contrasted with the absence of joint destruction, good functional tolerance, and moderate abnormalities of markers for inflammation. The location and rapid progression of the cyst-like lesions in this patient were highly unusual.     

类风湿关节炎骨破坏作用机制及中医药治疗研究进展

类风湿关节炎(RA)是一种累及多个关节的全身性自身免疫性疾病,常累及小关节,病变呈对称性、侵袭性和致残性,发病后期常易造成不可逆转的软骨、骨和其他邻近组织的破坏,最终导致严重的关节畸形甚至残疾,给患者及其家庭造成严重的身体和心理损害,严重影响生活质量。迄今为止,虽然治疗RA的药物很多,但RA仍然无法完全得到彻底根治,究其原因在于RA及其骨破坏的发病机制仍未完全明确。因此,对于RA骨破坏的发病机制及如何治疗显得格外重要。RA骨破坏的发病机制总的来说是成骨细胞与破骨细胞之间的失衡导致的,本文通过整理近年来参与RA关节软骨破坏及骨侵蚀病程的相关研究文献进行综述和讨论,分别从细胞因子/趋化因子、非编码RNA、信号通路等三个不同方面阐述了对成骨细胞与破骨细胞之间的作用造成RA骨破坏的发病机制,以期为RA骨破坏发病机制研究提供新的思路。中医药在预防RA骨破坏的发病过程中起着重要的作用,在保证疗效的前提下还能保证其安全性。因此,对于RA骨破坏的发病机制进行深入地研究及研究中医药在其治疗中的作用,为其治疗能够提供新的研究思路。     

Regulation of tumor necrosis factor-alpha and tumor necrosis factor converting enzyme in human osteoarthritis.

A snake venom-like protease isolated by a differential display screen between normal and osteoarthritis (OA)-affected cartilage (designated as cSVP) has a cDNA sequence identical to tumor necrosis factor (TNF)alpha convertase enzyme (TACE) and belongs to the adamalysin group of proteases. It has unique structural properties and when expressed in baculovirus, cleaves preferentially proTNFalpha to TNFalpha. The OA-affected cartilage has upregulated mRNA for TNFalpha and TACE as compared to normal cartilage. TNFalpha and TACE regulate inflammatory mediators in OA-affected cartilage which can be inhibited by both soluble TNFalpha receptors and inhibitors of TACE. These experiments demonstrate a functional paracrine/autocrine role of TNFalpha in OA-affected cartilage that is modulated by upregulated levels of chondrocyte-derived TACE.     

中药防治类风湿关节炎骨破坏的研究进展

类风湿关节炎(rheumatoid arthritis,RA)骨破坏伴随RA整个病程,一旦发生骨破坏、常规激素疗法效果有限而预后差。实验研究和临床应用已报道,中药防治类风湿关节炎骨破坏已取得一定成效,且中药的重要作用也引起学者的关注。本文对中药防治类风湿关节炎骨破坏的研究进展进行综述。     

烫伤后脂多糖受体CD14和肿瘤坏死因子-α基因表达的变化规律

目的 观察烫伤后机体主要脏器脂多糖受体ＣＤ１４（ＣＤ１４）和肿瘤坏死因子－α（ＴＮＦ－α）ｍＲＮＡ的表达的变化规律及二者的相互关系。方法 采用大鼠３５％Ⅲ度烫伤模型,分别于伤前,伤后１２,２４,４８,７２小时活杀动物,留取组织标本或分离腹腔巨噬细胞,检测组织或巨噬细胞ＣＤ１４,ＴＮＦ－αｍＲＮＡ表达。结果 烫伤后肝,肺,肾,肠等组织ＣＤ１４ｍＲＮＡ水平均有不同程度增高,分别于伤后１２小时和４８小时     

Impact of interleukin-1 receptor antagonist and tumor necrosis factor-alpha gene polymorphism on IgA nephropathy

BACKGROUND: It is evident that cytokines play an important role in the pathogenesis as well as disease progression in IgA nephropathy (IgAN). The level of cytokine production is influenced by different genotypes that reflect gene polymorphism of the pertinent cytokine. Interleukin-1 receptor antagonist (IL-1ra) and tumor necrosis factor-alpha (TNF-alpha) gene polymorphism have been found to affect disease susceptibility and activity in several inflammatory diseases. However, the impact of these polymorphisms in IgAN patients has not previously been thoroughly studied. METHODS: We investigated 111 cases of biopsy-proven IgAN and 100 healthy, normal controls for their IL-1ra and TNF-alpha gene polymorphism. IL-1ra gene polymorphism was characterized as a variable number of tandem repeats of a 86 bp sequence within intron 2. Five alleles were identified and were designated as IL1RN*1, IL1RN*2, IL1RN*3, IL1RN*4, and IL1RN*5, corresponding to 4, 2, 5, 3, 6 repeats, respectively. A polymorphism in the promoter region of the TNF-alpha gene was also studied. This polymorphism involved a guanidine to adenosine transition at position -308 and was designated as TNF1 (-308G) and TNF2 (-308A). RESULTS: There were 54 male and 57 female patients with a mean age of 30.3 +/- 12.5 years and a disease duration of 66. 8 +/- 47.2 months. The mean duration of the follow-up period was 47. 3 +/- 32.6 months. In the patient group, the allele frequencies of IL1RN*1, IL1RN*2, IL1RN*3, IL1RN*4, and IL1RN*5 were 89.6%, 9.9%, 0%, 0.5%, and 0%, respectively, whereas the corresponding carriage rates were 100%, 19.8%, 0%, 0.9%, and 0%, respectively. An excessive carriage of IL2RN*2 was found in the patients when compared with normal controls (allele frequency, 9.9 vs. 2.5%, P < 0.0001). The allele frequencies of TNF1 and TNF2 were 94.1 and 5.9%, respectively, and the carriage rates were 99.1 and 10.8%, respectively, in the patients, which was not significantly different from those of normal controls. When the patients were stratified into mild and severe groups according to their initial presentation, none of the studied alleles correlated with the severity. However, patients with gross hematuria were associated with a higher carriage rate of TNF2 when compared with patients without gross hematuria (allele frequency, 15. 4 vs. 4.6%, P = 0.0552; carriage rate, 30.8% vs. 8.2%, P = 0.0272). Renal survival analysis revealed that the TNF2 carrier had a renal survival comparable with TNF2 (-) patients. However, the carriage of the IL1RN*2 allele was associated with a significantly poorer long-term outcome with a median survival time of 72 months, as compared with those without IL1RN*2 (134 months, P < 0.01). CONCLUSION: IL-1ra and TNF-alpha gene polymorphism may affect disease susceptibility as well as disease activity and long-term outcome in human IgAN. Treatment with an IL-1ra or IL-1 blocking agent may be relevant in those carrying the IL1RN*2 allele.     

Soluble glucocorticoid-induced tumor necrosis factor receptor (sGITR) stimulates osteoclast differentiation in response to receptor activator of NF-kappaB ligand (RANKL) in osteoclast cells

We found that treatment of osteoclast (OC) precursors with soluble glucocorticoid-induced tumor necrosis factor receptor (sGITR) promoted osteoclastogenesis in the presence of macrophage colony-stimulating factor (M-CSF) and receptor for activation of nuclear factor-kappaB ligand (RANKL). Low levels of GITR and its ligand were expressed on the surface of OC precursor cells after incubation with RANKL. Stimulation of osteoclastogenesis by sGITR was blocked by neutralization with anti-GITR ligand antibody (Ab), whereas endogenous GITR did not affect osteoclastogenesis, indicating that enhancement of osteoclastogenesis by sGITR involves signaling via GITR ligand. The addition of sGITR decreased the level of interferon (IFN)-beta, and blockade of endogenous IFN-beta did not affect osteoclastogenesis stimulated by sGITR. We conclude that sGITR enhances osteoclastogenesis by acting on OC precursor cells to lower the level of IFN-beta.