Spontaneous generation of functional osteoclasts from synovial fluid mononuclear cells as a model of inflammatory osteoclastogenesis

In osteoimmunology, osteoclastogenesis is understood in the context of the immune system. Today, the in vitro model for osteoclastogenesis necessitates the addition of recombinant human receptor activator of nuclear factor kappa‐B ligand (RANKL) and macrophage colony‐stimulating factor (M‐CSF). The peripheral joints of patients with rheumatoid arthritis (RA) and spondyloarthritis (SpA) are characterized by an immune‐mediated inflammation that can lead to bone destruction. Here, we evaluate spontaneous in vitro osteoclastogenesis in cultures of synovial fluid mononuclear cells (SFMCs) activated only in vivo. SFMCs were isolated and cultured for 21 days at 0.5–1.0 × 10⁶ cells/mL in culture medium. SFMCs and healthy control peripheral blood monocytes were cultured with RANKL and M‐CSF as controls. Tartrate‐resistant acid phosphatase (TRAP) positive multinucleated cells were found in the SFMC cultures after 21 days. These cells expressed the osteoclast genes calcitonin receptor, cathepsin K, and integrin β3, formed lacunae on dentin plates and secreted matrix metalloproteinase 9 (MMP9) and TRAP. Adding RANKL and M‐CSF potentiated this secretion. In conclusion, we show that SFMCs from inflamed peripheral joints can spontaneously develop into functionally active osteoclasts ex vivo. Our study provides a simple in vitro model for studying inflammatory osteoclastogenesis.     

血清窖蛋白-1在慢性阻塞性肺疾病相关肺动脉高压患者中的表达及意义

目的 研究血清窖蛋白-1 （Cav-1） 在慢性阻塞性肺疾病 （COPD） 相关肺动脉高压 （PAH） 患者中的表达及其意义。方法 选取稳定期COPD患者65例， 根据是否合并PAH分成COPD组 ［肺动脉收缩压 （PASP） ＜40 mmHg， 35例］ 及COPD-PAH组 （PASP ≥40 mmHg， 30例）。另选取在本院健康体检的志愿者30例作为对照组。对比各组基线资料、 动脉血气分析、 肺功能指标， 以及血清Cav-1、 白细胞介素 （IL） -6和肿瘤坏死因子-α （TNF-α） 的表达水平。绘制受试者工作特征 （ROC） 曲线， 评价Cav-1对COPD合并PAH的诊断价值。结果 COPD-PAH组与COPD组第一秒用力呼吸容积 （FEV1） /用力肺活量 （FVC）、 FEV1占预计值百分比 （FEV1%） 及氧分压 ［p （O2 ）］ 低于对照组， 而二氧化碳分压 ［p （CO2 ）］、 PASP均高于对照组 （P＜0.01）。COPD-PAH组p （O2 ） 低于COPD组， p （CO2 ）、 PASP均高于COPD 组 （P＜0.01）。对照组、 COPD组及COPD-PAH组Cav-1表达水平呈逐渐降低趋势， 而IL-6、 TNF-α表达水平呈逐渐升高趋势 （P＜0.01）。血清Cav-1诊断COPD合并PAH的ROC曲线下面积为0.902 （0.821～0.955）， 最佳截断值为 6.66 μg/L， 此时诊断敏感度为76.7%， 特异度为85.7%， 与多普勒超声诊断仪测量PASP结果比较一致性较好 （Kappa 值=0.627）。结论 血清Cav-1在COPD相关PAH患者表达明显下调， 可以作为预测COPD相关PAH的新型血清标志物。     

Prognostic tools for hypertrophic scar formation based on fundamental differences in systemic immunity

Unpredictable hypertrophic scarring (HS) occurs after approximately 35% of all surgical procedures and causes significant physical and psychological complaints. Parallel to the need to understanding the mechanisms underlying HS formation, a prognostic tool is needed. The objective was to determine whether (systemic) immunological differences exist between patients who develop HS and those who develop normotrophic scars (NS) and to assess whether those differences can be used to identify patients prone to developing HS. A prospective cohort study with NS and HS groups in which (a) cytokine release by peripheral blood mononuclear cells (PBMC) and (b) the irritation threshold (IT) after an irritant (sodium lauryl sulphate) patch test was evaluated. Univariate regression analysis of PBMC cytokine secretion showed that low MCP‐1, IL‐8, IL‐18 and IL‐23 levels have a strong correlation with HS (P < .010‐0.004; AUC = 0.790‐0.883). Notably, combinations of two or three cytokines (TNF‐a, MCP‐1 and IL‐23; AUC: 0.942, Nagelkerke R²: 0.727) showed an improved AUC indicating a better correlation with HS than single cytokine analysis. These combination models produce good prognostic results over a broad probability range (sensitivity: 93.8%, specificity 86.7%, accuracy 90,25% between probability 0.3 and 0.7). Furthermore, the HS group had a lower IT than the NS group and an accuracy of 68%. In conclusion, very fundamental immunological differences exist between individuals who develop HS and those who do not, whereas the cytokine assay forms the basis of a predictive prognostic test for HS formation, the less invasive, easily performed irritant skin patch test is more accessible for daily practice.     

The neurobiology of chronic pain states

Plasticity enables alterations in transmission in nociceptive systems. It is this plasticity in the nervous system that can alter the linear relation between noxious stimuli and the perception of pain and is important in the switch from acute to chronic pain. In this way, a number of CNS mechanisms can alter neuronal activity, leading to abnormal ongoing and stimulus-evoked pains due to peripheral and central changes. Peripheral nerves can become sensitized, spinal cord neurons can be rendered hyperexcitable and ascending projections to higher centres can further trigger changes in descending controls from the midbrain and brainstem. Together, these changes, all of which appear to involve reversible physiological and pharmacological plasticity, can alter the relationship between an applied stimulus and the perceived response and so lead to persistent pain states.     

Control of immunity and allergy by steroid hormones

Steroid hormones, especially glucocorticoids, androgens, and estrogens, have profound influence on immunity. Recent studies using cell-type specific steroid hormone receptor-deficient mice have revealed the precise roles of some of these hormones in the immune system. Glucocorticoids are known to have strong anti-inflammatory and immunosuppressive effects and pleiotropic effects on innate and adaptive immune responses. They suppress the production of inflammatory cytokines by macrophages and DCs and the production of IFN-γ by NK cells, thus inhibiting innate immunity. By contrast, glucocorticoids enhance the immune response by inducing the expression of IL-7R and CXCR4 in T cells and the accumulation of T cells in lymphoid organs in accordance with the diurnal change of the glucocorticoid concentration. Thus, glucocorticoids suppress innate immunity but enhance adaptive immunity. Androgens suppress the homeostasis and activation of ILC2s and the differentiation of Th2 and Th17 cells and enhance the suppressive function of Tregs, thereby alleviating allergic airway inflammation. Thus, these steroid hormones have pleiotropic functions in the immune system. Further investigations are awaited on the regulation of immunity and allergy by estrogens using cell-specific steroid hormone receptor-deficient mice.     

Trade-offs between acquired and innate immune defenses in humans

Immune defenses provide resistance against infectious disease that is critical to survival. But immune defenses are costly, and limited resources allocated to immunity are not available for other physiological or developmental processes. We propose a framework for explaining variation in patterns of investment in two important subsystems of anti-pathogen defense: innate (non-specific) and acquired (specific) immunity. The developmental costs of acquired immunity are high, but the costs of maintenance and activation are relatively low. Innate immunity imposes lower upfront developmental costs, but higher operating costs. Innate defenses are mobilized quickly and are effective against novel pathogens. Acquired responses are less effective against novel exposures, but more effective against secondary exposures due to immunological memory. Based on their distinct profiles of costs and effectiveness, we propose that the balance of investment in innate versus acquired immunity is variable, and that this balance is optimized in response to local ecological conditions early in development. Nutritional abundance, high pathogen exposure and low signals of extrinsic mortality risk during sensitive periods of immune development should all favor relatively higher levels of investment in acquired immunity. Undernutrition, low pathogen exposure, and high mortality risk should favor innate immune defenses. The hypothesis provides a framework for organizing prior empirical research on the impact of developmental environments on innate and acquired immunity, and suggests promising directions for future research in human ecological immunology.