Plasma cytokine profile in tropical endomyocardial fibrosis: predominance of TNF-a, IL-4 and IL-10

Expression of miR-21 &IL-4 in endometriosis

BACKGROUND

Endometriosis characterized with existence of endometrial-like tissue outside the uterus. Fibrosis of ectopic lesions is an important feature of endometriosis. IL-4 induces fibrosis via fibroblast proliferation, collagen production and myofibroblast differentiation. Increasing of miR-21 expression promotes fibroblast activation and fibrosis expansion. The aim of study was to evaluate the expression of miR-21 and its relationship with IL-4 gene expression in endometrial ectopic and eutopic tissues of endometriosis patients.

METHODS AND RESULTS

Ectopic and eutopic tissue samples were taken from 20 women with endometriosis, and control samples were taken from the endometrium of 20 endometriosis-free women. The relative expression of IL-4 and miR-21 evaluated by Real Time PCR. IL-4 relative gene expression was significantly increased in ectopic tissue compared to eutopic (p = 0.025) and control tissue (p = 0.021). The relative expression of miR-21 gene in ectopic tissue was increased compared to eutopic (p = 0.850) and control tissue (p = 0.978) but these differences were not significant. Also, the correlation between IL-4 and miR-21 relative gene expression was not significant (p = 0.083).

CONCLUSION

The increased expression of miR-21 in endometrium of women with endometriosis may upregulate the IL-4 gene expression and lead to fibrosis. Further studies may suggest miR-21 and IL-4 as candidates for diagnosis of endometriosis.

Challenges in addressing the knowledge gap on endomyocardial fibrosis through community-based studies

Endomyocardial fibrosis (EMF) is a poverty-related disease of unknown origin that afflicts predominantly young people of certain rural areas in low-income countries and can be used to expose global disparities in cardiovascular research. Despite affecting predominantly young people and causing high morbidity and mortality, efforts to understand its mechanisms and natural history have been hampered by the incapacity to detect the early stages of the disease in endemic areas. Dietary, environmental and infectious factors seem to combine in susceptible individuals to give rise to an inflammatory process that leads to endomyocardial damage and scar formation. Lack of awareness by health professionals and low access to health care determine late diagnosis, when complications such as chronic heart failure, thromboembolism and arrhythmia are already present. Open-heart surgery to detach the endocardial fibrous tissue and repair the atrioventricular valve, remains the last resource to prolong patients' survival. Community-based research is therefore needed to understand the epidemiology of EMF, detect early disease, uncover its pathogenesis and explore new therapeutic targets. Our research has shown that echocardiographic screening using standard criteria adds sensitivity and precision to the diagnosis, particularly in asymptomatic disease, providing an opportunity for longitudinal community-based research. However, researchers face major constraints in rural settings where EMF is endemic, including socioeconomic, cultural, geographical and administrative barriers. In presenting our experience we aim to describe the challenges and discuss the lessons learned while implementing community-based research in a highly endemic area in southern Mozambique, one of the poorest countries in the world. Additionally, we discuss how recent advances in medicine-such as use of point-of-care diagnostics, heart failure biomarkers and new imaging techniques-may open new possibilities for high quality research through collaborative partnerships and regional initiatives.

Role of cytokines and inflammation in heart function during health and disease

By virtue of their actions on NF-κB, an inflammatory nuclear transcription factor, various cytokines have been documented to play important regulatory roles in determining cardiac function under both physiological and pathophysiological conditions. Several cytokines including TNF-α, TGF-β, and different interleukins such as IL-1 IL-4, IL-6, IL-8, and IL-18 are involved in the development of various inflammatory cardiac pathologies, namely ischemic heart disease, myocardial infarction, heart failure, and cardiomyopathies. In ischemia-related pathologies, most of the cytokines are released into the circulation and serve as biological markers of inflammation. Furthermore, there is an evidence of their direct role in the pathogenesis of ischemic injury, suggesting cytokines as potential targets for the development of some anti-ischemic therapies. On the other hand, certain cytokines such as IL-2, IL-4, IL-6, IL-8, and IL-10 are involved in the post-ischemic tissue repair and thus are considered to exert beneficial effects on cardiac function. Conflicting reports regarding the role of some cytokines in inducing cardiac dysfunction in heart failure and different types of cardiomyopathies seem to be due to differences in the nature, duration, and degree of heart disease as well as the concentrations of some cytokines in the circulation. In spite of extensive research work in this field of investigation, no satisfactory anti-cytokine therapy for improving cardiac function in any type of heart disease is available in the literature.

T-Helper 2 Lymphocyte Immunophenotype Is Associated With Iatrogenic Laryngotracheal Stenosis

OBJECTIVE/HYPOTHESIS

This prospective controlled human and murine study assessed the presence of inflammatory cells and cytokines to test the hypothesis that immune cells are associated with fibroproliferation in iatrogenic laryngotracheal stenosis (iLTS).

METHODS

Inflammation was assessed by histology and immunofluorescence (IF), quantitative real-time polymerase chain reaction (qRT-PCR), and flow cytometry of cricotracheal resections of iLTS patients compared to normal controls. An iLTS murine model assessed the temporal relationship between inflammation and fibrosis.

RESULTS

iLTS specimens showed increased inflammation versus normal controls (159/high power field [hpf] vs. 119/hpf, P = 0.038), and increased CD3 + T-cells, CD4 + cells, and CD3+/CD4 + T-helper (T_H ) cells (all P < 0.05). The inflammatory infiltrate was located immediately adjacent to the epithelial surface in the superficial aspect of the thickened lamina propria. Human flow cytometry and qRT-PCR showed a significant increase in interleukin (IL)-4 gene expression, indicating a T_H 2 phenotype. Murine IF revealed a dense CD4 + T-cell inflammatory infiltrate on day 4 to 7 postinjury, which preceded the development of fibrosis. Murine flow cytometry and qRT-PCR studies mirrored the human ones, with increased T-helper cells and IL-4 in iLTS versus normal controls.

CONCLUSION

CD3/CD4 + T-helper lymphocytes and the proinflammatory cytokine IL-4 are associated with iLTS. The association of a T_H 2 immunophenotype with iLTS is consistent with findings in other fibroinflammatory disorders. The murine results reveal that the inflammatory infiltrate precedes the development of fibrosis. However, human iLTS specimens with well-developed fibrosis also contain a marked chronic inflammatory infiltrate, suggesting that the continued release of IL-4 by T-helper lymphocytes may continue to propagate iLTS.

LEVEL OF EVIDENCE

NA Laryngoscope, 129:177-186, 2019.

Changes in pro-inflammatory cytokine levels and late-life depression: A two year population based longitudinal study

Longitudinal associations of cytokine levels with depression are unclear. This study aimed to investigate cross-sectional and prospective associations between five serum pro-inflammatory cytokine levels and late-life depression. 732 Korean people aged 65+ were evaluated at baseline. Of 631 without depression (Geriatric Mental State schedule) at baseline, 521 (83%) were followed over a 2 year period and incident depression was ascertained. Serum tumor necrosis factor-α, interleukin (IL)-1α, IL-1β, IL-6, and IL-8 levels were assayed at both baseline and follow-up. Associations between cytokine levels and depressive status were evaluated using linear regression models, considering potential covariates (demographics, cognitive function, disability, lifestyle factors, and vascular risk factors) and applying Bonferroni corrections. Prevalent depression at baseline was significantly associated with higher contemporaneous levels of IL-1β and IL-8, independent of relevant covariates and after applying Bonferroni corrections. In the analyses of the five cytokine levels in combination, independent associations were found between prevalent depression and increased numbers of cytokines at higher levels at baseline. Incident depression was significantly associated with increases in IL-1β, IL-6, and IL-8 levels during the follow-up independent of relevant covariates and after applying Bonferroni corrections. In combination analyses, incident depression was independently associated with higher numbers of cytokines showing increasing levels over the same follow-up period. However, incident depression was not predicted by higher baseline pro-inflammatory cytokine levels in any analysis. Our findings suggest that depression might affect serum cytokines alterations and lead to inflammatory processes in late-life.

Cytokine Interferon-γ suppresses the function of capsule myofibroblasts and induces cell apoptosis

Myofibroblasts (MFs), a contractile subset of fibroblasts, play a pivotal role in physiological wound healing and in the development of many fibroconnective disorders. The complex cytokine network regulating the function of MFs in joint stiffness is still poorly understood. In this in vitro study, we investigated the effect of the cytokine Interferon-gamma (IFN-γ) on MFs isolated from human joint capsules. MFs were cultivated either in the presence of increasing concentrations of IFN-γ alone or in combination with IFN-γ neutralizing antibodies. Cell viability, cytotoxicity, apoptosis, and mRNA gene expression of the MF markers alpha-smooth muscle actin (α-SMA) and collagen type I were analyzed in MF cultures. Contraction potential was analyzed in an established collagen gel contraction assay simulating the extracellular matrix. Using immunofluorescence staining, we could verify that MFs express IFN-γ-receptor (R)-1 on their membrane. IFN-γ decreased MF viability and significantly elevated the apoptosis rate in a dose-dependent manner. IFN-γ down-regulated α-SMA and collagen type I mRNA expression which was associated with a diminished MF mediated contraction of the gel matrices. These effects were suppressed by simultaneous treatment of cells with a neutralizing IFN-γ antibody. Our experiments confirm the hypothesis that the cytokine IFN-γ is a crucial component of the regulatory network of capsule MFs. IFN-γ notably influences the ability of MFs to contract collagen matrices by suppressing α-SMA gene expression. IFN-γ is toxic for MFs in high concentrations and may negatively regulate the number of pro-fibrotic MFs during the healing process via induction of cell apoptosis. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2524-2533, 2017.

Influence of the anti-inflammatory cytokine interleukin-4 on human joint capsule myofibroblasts

Post-traumatic joint contracture was reported to be associated with elevated numbers of contractile myofibroblasts (MFs) in the healing capsule. During the physiological healing process, the number of MFs declines; however, in fibroconnective disorders, MFs persist. The manifold interaction of the cytokines regulating the appearance and persistence of MFs in the pathogenesis of joint contracture remains to be elucidated. The objective of our current study was to analyze the impact of the anti-inflammatory cytokine interleukin (IL)-4 on functional behavior of MFs. Cells were isolated from human joint capsule specimens and challenged with three different concentrations of IL-4 with or without its neutralizing antibody. MF viability, contractile properties, and the gene expression of both alpha-smooth muscle actin (α-SMA) and collagen type I were examined. Immunofluorescence staining revealed the presence of IL-4 receptor (R)-alpha (α) on the membrane of cultured MFs. The cytokine IL-4 promoted MF viability and enhanced MF modulated contraction of collagen gels. Moreover, IL-4 intervened in gene expression by up-regulation of α-SMA and collagen type I mRNA. These effects could be specifically lowered by the neutralizing IL-4 antibody. On the basis of our findings we conclude that the anti-inflammatory cytokine IL-4 specifically regulates viability and the contractile properties of MFs via up-regulating the gene expression of α-SMA and collagen type I. IL-4 may be a helpful target in developing anti-fibrotic therapeutics for post-traumatic joint contracture in human. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1290-1298, 2017.

Bufei Huoxue Capsule Attenuates PM2.5-Induced Pulmonary Inflammation in Mice

Atmospheric fine particulate matter 2.5 (PM 2.5) may carry many toxic substances on its surface and this may pose a public health threat. Epidemiological research indicates that cumulative ambient PM2.5 is correlated to morbidity and mortality due to pulmonary and cardiovascular diseases and cancer. Mitigating the toxic effects of PM2.5 is therefore highly desired. Bufei Huoxue (BFHX) capsules have been used in China to treat pulmonary heart disease (cor pulmonale). Thus, we assessed the effects of BFHX capsules on PM2.5-induced pulmonary inflammation and the underlying mechanisms of action. Using Polysearch and Cytoscape 3.2.1 software, pharmacological targets of BFHX capsules in atmospheric PM2.5-related respiratory disorders were predicted and found to be related to biological pathways of inflammation and immune function. In a mouse model of PM2.5-induced inflammation established with intranasal instillation of PM2.5 suspension, BFHX significantly reduced pathological response and inflammatory mediators including IL-4, IL-6, IL-10, IL-8, TNF-α, and IL-1β. BFHX also reduced keratinocyte growth factor (KGF), secretory immunoglobulin A (sIgA), and collagen fibers deposition in lung and improved lung function. Thus, BFHX reduced pathological responses induced by PM2.5, possibly via regulation of inflammatory mediators in mouse lungs.

Multiplex single molecule counting technology used to generate interleukin 4, interleukin 6, and interleukin 10 reference limits

Detecting biomarkers at pg/ml concentrations or below is, in many situations, critical for quantifying levels in healthy individuals as well as the changes that can occur in the progression of disease states. The ability to detect multiple biomarkers from the same sample allows for better diagnoses, more efficient testing, and lower volumes of sample required. Based on single molecule counting technology, a multiplex instrument was designed and built that is capable of detecting cytokines and other low-abundance proteins at sub-pg/ml quantities in human plasma samples. The multiplex single molecule counting instrument was used to generate 95% reference limits for interleukin 4 (IL-4, <0.61 pg/ml), interleukin 6 (IL-6, <6.53 pg/ml), and interleukin 10 (IL-10, <1.08 pg/ml) from 100 healthy human donor plasma samples, with more than 90% of IL-4 concentrations and 100% of IL-6 and IL-10 concentrations above the limit of detection.