Interleukin-10: an anti-inflammatory cytokine with therapeutic potential

Beyond muscles: Investigating immunoregulatory myokines in acute resistance exercise - A systematic review and meta-analysis

Myokines, released from the muscle, enable communication between the working muscles and other tissues. Their release during physical exercise is assumed to depend on immune-hormonal-metabolic interactions concerning mode (endurance or resistance exercise), duration, and intensity. This meta-analysis aims to examine the acute changes of circulating myokines inducing immunoregulatory effects caused by a bout of resistance exercise and to consider potential moderators of the results. Based on this selection strategy, a systematic literature search was conducted for resistance exercise intervention studies measuring interleukin (IL-) 6, IL-10, IL-1ra, tumor necrosis factor (TNF-) α, IL-15, IL-7, transforming growth factor (TGF-) β1, and fractalkines (FKN) before and immediately after resistance exercise in healthy individuals. Random-effects meta-analysis was performed for each myokine. We identified a moderate positive effect of resistance exercise for IL-6 and IL-1ra. Regarding IL-15 and TNF-α, small to moderate effects were found. For IL-10, no significant effect was observed. Due to no data, meta-analyses for IL-7, TGF-β1, and FKN could not be performed. No moderators (training status, type of exercise, risk of bias, age, sex, time of day, exercise volume, exercise intensity, exercise dose) of the results were detected for all tested myokines. Taken together, this systematic review and meta-analysis showed immediate positive effects of an acute resistance exercise session on IL-6, IL-1ra, TNF-α, and IL-15 levels.

Physical exercise in kidney disease: A commonly undervalued treatment modality

BACKGROUND

Physical inactivity has been identified as a risk factor for multiple disorders and a strong association exists between chronic kidney disease (CKD) and a sedentary lifestyle. Even though physical activity is crucial in the development and progression of disease, the general focus of the current medical practice is the pharmacological perspective of diseases with inadequate emphasis on lifestyle intervention.

METHODS

In this narrative review we explain the pathophysiological mechanisms underlying the beneficial effects of physical exercise on CKD in addition to discussing the clinical studies and trials centred on physical exercise in patients with CKD.

RESULTS

Physical activity influences several pathophysiological mechanisms including inflammation, oxidative stress, vascular function, immune response and macromolecular metabolism. While exercise can initially induce stress responses like inflammation and oxidative stress, long-term physical activity leads to protective countermeasures and overall improved health. Trials in pre-dialysis CKD patients show that exercise can lead to reductions in body weight, inflammation markers and fasting plasma glucose. Furthermore, it improves patients' functional capacity, cardiorespiratory fitness and quality of life. The effects of exercise on kidney function have been inconsistent in these trials. In haemodialysis, peritoneal dialysis and kidney transplant patients exercise interventions improve cardiorespiratory fitness, walking capacity and quality of life. Combined training shows the best performance to increase peak oxygen uptake in haemodialysis patients. In kidney transplant recipients, exercise improves walking performance, quality of life and potentially arterial stiffness. However, exercise does not affect glucose metabolism, serum cholesterol and inflammation biomarkers. Long-term, adequately powered trials are needed to determine the long-term feasibility, and effects on quality of life and major clinical outcomes, including mortality and cardiovascular risk, in all CKD stages and particularly in kidney transplant patients, a scarcely investigated population.

CONCLUSION

Physical exercise plays a crucial role in ameliorating inflammation, oxidative stress, vascular function, immune response and macromolecular metabolism, and contributes significantly to the quality of life for patients with CKD, irrespective of the treatment and stage. Its direct impact on kidney function remains uncertain. Further extensive, long-term trials to conclusively determine the effect of exercise on major clinical outcomes such as mortality and cardiovascular risk remain a research priority.

Prospective longitudinal analysis of clinical and immunological risk factors associated with oral and gastrointestinal mucositis following autologous stem cell transplant in adults

PURPOSE

The study aimed to characterize the incidence of both oral and gastrointestinal (GI) mucositis, its' associated temporal changes in local and systemic pro-inflammatory cytokines, and to explore predictive clinical and immunological factors associated with their occurrences in hematopoietic stem cell transplant (HSCT).

METHODS

Autologous HSCT patients aged 18 years old and above were recruited from Hospital Ampang, Malaysia, between April 2019 to December 2020. Mucositis assessments were conducted daily, whilst blood and saliva were collected prior to conditioning regimen, on Day 0, Day+7 and 6-month. Baseline and inflammatory predictors in a repeated time measurement of moderate-severe mucositis were assessed by multiple logistic regression and generalized estimating equations, respectively.

RESULTS

Of the 142 patients analyzed, oral mucositis and diarrhea (representing GI mucositis) were reported as 68.3% and 95.8%, respectively. Predictive factors for moderate-severe oral mucositis were BEAM or busulphan-based regimens (odds ratio (OR)=9.2, 95% confidence interval (CI)=1.16-72.9, p-value (p) = 0.005) and vomiting (OR=4.6, 95% CI 1.68-12.3, p = 0.004). Predictive factors for moderate-severe GI mucositis were BEAM or busulphan-based regimens (OR=3.9, 95% CI 1.05-14.5, p = 0.023), female sex (OR = 3.3, 95% CI 1.43-7.44, p = 0.004) and body mass index (OR=1.08, 95% CI 1.02-1.15, p = 0.010). Cytokines analyses were performed in 96 patients. Saliva and plasma interleukin-6 (OR=1.003, 95% CI 1.001-1.004, p < 0.001 and OR=1.01, 95% CI 1.001-1.015, p = 0.029), and plasma tumor necrosis factor-alpha (OR=0.91, 95% CI 0.85-0.99, p = 0.019) were predictive of moderate-severe oral mucositis in a time-dependent model.

CONCLUSION

This study provides real-world evidence and insights into patient- and treatment-related factors affecting oral and GI mucositis in HSCT.

Cytokines as Biomarkers for Evaluating Physical Exercise in Trained and Non-Trained Individuals: A Narrative Review

Physical activity and exercise training have numerous health benefits, including the prevention and management of chronic diseases, improvement of cardiovascular health, and enhancement of mental well-being. However, the effectiveness of training programs can vary widely among individuals due to various factors, such as genetics, lifestyle, and environment. Thus, identifying reliable biomarkers to evaluate physical training effectiveness and personalize training programs is crucial. Cytokines are signaling molecules produced by immune cells that play a vital role in inflammation and tissue repair. In recent years, there has been increasing interest in the potential use of cytokines as biomarkers for evaluating training effectiveness. This review article aims to provide an overview of cytokines, their potential as biomarkers, methods for measuring cytokine levels, and factors that can affect cytokine levels. The article also discusses the potential benefits of using cytokines as biomarkers, such as monitoring muscle damage and inflammation, and the potential for personalized training programs based on cytokine responses. We believe that the use of cytokines as biomarkers holds great promise for optimizing training programs and improving overall health outcomes.

MicroRNAs and Efferocytosis: Implications for Diagnosis and Therapy

About 10-100 billion cells are generated in the human body in a day, and accordingly, 10-100 billion cells predominantly die for maintaining homeostasis. Dead cells generated by apoptosis are also rapidly engulfed by macrophages (Mθs) to be degraded. In case of the inefficient engulfment of apoptotic cells (ACs) via Mθs, they experience secondary necrosis and thus release intracellular materials, which display damage-associated molecular patterns (DAMPs) and result in diseases. Over the last decades, researchers have also reflected on the significant contribution of microRNAs (miRNAs) to autoimmune diseases through the regulation of Mθs functions. Moreover, miRNAs have shown intricate involvement with completely adjusting basic Mθs functions, such as phagocytosis, inflammation, efferocytosis, tumor promotion, and tissue repair. In this review, the mechanism of efferocytosis containing "Find-Me", "Eat-Me", and "Digest-Me" signals is summarized and the biogenesis of miRNAs is briefly described. Finally, the role of miRNAs in efferocytosis is discussed. It is concluded that miRNAs represent promising treatments and diagnostic targets in impaired phagocytic clearance, which leads to different diseases.

Using Linear Discriminant Analysis to Characterize Novel Single Nucleotide Polymorphisms and Expression Profile Changes in Genes of Three Breeds of Rabbit (Oryctolagus cuniculus)

The objectives of this study were to investigate polymorphisms and changes in expression patterns of the genes FGF5, PGAM2, TLR2 and IL10 in V-line, Baladi Black and Baladi Red rabbits. Blood samples were collected from 180 healthy rabbits (n = 60 for each breed) for DNA extraction and DNA sequencing. At 3 mo of age, 20 randomly selected females from each breed were euthanized for gene expression quantification in muscle and spleen samples. PCR-DNA sequencing revealed single nucleotide polymorphisms (SNPs) among the 3 breeds that provided a monomorphic pattern for 3 of the 4 genes analyzed. Linear discriminant analysis (LDA) was used to classify the SNPs of these genes in the 3 breeds. The overall percentage of correctly classified cases for the model was 75%, with percentages of 100% for FGF5, 63% for IL10, and 100% for TLR2. Breed was a significant predictor for gene classification with estimation (1.00). Expression profiles of the genes were higher in V-line as compared with Baladi Black or Baladi Red. The LDA discriminated the 3 breeds using results of the gene expression profile as predictors for classification. Overall, 73% of the cases were correctly classified by gene expression. The identified SNPs, along with changes in mRNA levels of FGF5, PGAM2, TLR2, and IL10, could provide a biomarker for efficient characterization of rabbit breeds and could thus help develop marker assisted selection for growth and immune traits in rabbits.

Modeling the circadian regulation of the immune system: Sexually dimorphic effects of shift work

The circadian clock exerts significance influence on the immune system and disruption of circadian rhythms has been linked to inflammatory pathologies. Shift workers often experience circadian misalignment as their irregular work schedules disrupt the natural light-dark cycle, which in turn can cause serious health problems associated with alterations in genetic expressions of clock genes. In particular, shift work is associated with impairment in immune function, and those alterations are sex-specific. The goal of this study is to better understand the mechanisms that explain the weakened immune system in shift workers. To achieve that goal, we have constructed a mathematical model of the mammalian pulmonary circadian clock coupled to an acute inflammation model in the male and female rats. Shift work was simulated by an 8h-phase advance of the circadian system with sex-specific modulation of clock genes. The model reproduces the clock gene expression in the lung and the immune response to various doses of lipopolysaccharide (LPS). Under normal conditions, our model predicts that a host is more sensitive to LPS at circadian time (CT) CT12 versus CT0 due to a dynamic change of Interleukin 10 (IL-10), an anti-inflammatory cytokine. We identify REV-ERB as a key modulator of IL-10 activity throughout the circadian day. The model also predicts a reversal of the times of lowest and highest sensitivity to LPS, with males and females exhibiting an exaggerated response to LPS at CT0, which is countered by a blunted immune response at CT12. Overall, females produce fewer pro-inflammatory cytokines than males, but the extent of sequelae experienced by males and females varies across the circadian day. This model can serve as an essential component in an integrative model that will yield mechanistic understanding of how shift work-mediated circadian disruptions affect the inflammatory and other physiological responses.

Phagocytosis of apoptotic endothelial cells reprograms macrophages in skin wounds

In healing wounds, the regression of blood vessels during the resolution phase creates a significant number of apoptotic endothelial cells (ApoECs). Surprisingly few studies have investigated the fate of apoECs in wounds, or the consequence of their removal. The current study employed both in vitro and in vivo models to investigate if macrophages ingest apoECs and to determine if such phagocytosis alters macrophage phenotype. To examine the capability of macrophages to ingest apoECs in in vivo wounds, pHrodo green labeled apoECs were injected into skin wounds 6 days after injury. The results demonstrated that 2.2% of macrophages in the wounds had engulfed apoECs 24 hours after injection. Macrophages that had engulfed apoECs expressed the markers CD80 (100%), CD86 (93.8%), and CD163 (22.8%), while no expression of CD206 marker was observed. In in vitro studies, 76.1% and 81.1% of PMA differentiated THP-1 macrophages engulfed apoECs at 6 and 24 hours, respectively. mRNA expression levels of IL-1β, iNOS, and TGF-β1 decreased in THP-1 macrophages after exposure to apoECs, while the expression of IL-6 increased. THP-1 macrophages that were incubated with apoECs for 6hours expressed CD80 (30.2%), CD163 (62.9%), and CD206 (45.3%), while expression levels in untreated group were 0.5%, 45.0%, and 2.4%, respectively. Taken together, our studies showed that macrophages phagocytize dermal apoECs both in vitro and in vivo. The engulfment of apoECs leads to a unique macrophage phenotype, which has characteristics of both M1 and M2 macrophage phenotypes. These findings provide a new mechanism by which macrophage phenotypes can be modified during wound resolution.

Anti-Inflammatory Effects of Exercise on Metabolic Syndrome Patients: A Systematic Review and Meta-Analysis

BACKGROUND

Increments in inflammatory indicators and low levels of physical activity are correlated to the expansion of the metabolic syndrome (MetS).

OBJECTIVE

The purpose of this study was to establish if exercise training ameliorates inflammatory status in MetS patients.

DATA SOURCES

PubMed, CINAHL, and Medline, Google Scholar, and Scopus databases and reference lists of included studies were searched.

STUDY SELECTION

Twenty randomized controlled trials (RCTs) of exercise-training impact on inflammatory markers (tumor necrosis factor (TNF) α, C-reactive protein (CRP), interleukin (IL) 6, IL-8, IL-10, and IL-18) with concurrent control groups were included in this analysis.

RESULTS

Results demonstrated an overall significant decrease in serum levels of TNF-α (mean difference (MD): -1.21 pg/ml; 95% confidence interval (CI): -1.77, -0.66), CRP (MD: -0.52 mg/l; 95% CI: -0.79, -0.25), IL-8 (MD: -1.31 pg/ml; 95% CI: -2.57, -0.06), and a significant increase in IL-10 (MD: 0.48 pg/ml; 95% CI: 0.10, 0.86). But exercise training did not change the level of IL-6 (MD: -0.69 pg/ml; 95% CI: -1.53, 0.14) and IL-18 (MD: -53.01 pg/ml; 95% CI: -166.64, 60.62).

CONCLUSION

Exercise training improves TNF-α, CRP, IL-8, and IL-10 levels in patients with MetS. For some variables, isolated aerobic exercise, and combined aerobic and resistance exercise appears to be optimal. Future research is needed to clarify the mechanisms underlying exercise training's effect on this population's inflammatory markers. More studies are required to confirm these findings.

Exercise as an anti-inflammatory therapy for cancer cachexia: a focus on interleukin-6 regulation

Cancer cachexia is a complicated disorder of extreme, progressive skeletal muscle wasting. It is directed by metabolic alterations and systemic inflammation dysregulation. Numerous studies have demonstrated that increased systemic inflammation promotes this type of cachexia and have suggested that cytokines are implicated in the skeletal muscle loss. Exercise is firmly established as an anti-inflammatory therapy that can attenuate or even reverse the process of muscle wasting in cancer cachexia. The interleukin IL-6 is generally considered to be a key player in the development of the microenvironment of malignancy; it promotes tumor growth and metastasis by acting as a bridge between chronic inflammation and cancerous tissue and it also induces skeletal muscle atrophy and protein breakdown. Paradoxically, a beneficial role for IL-6 has also been identified recently, and that is its status as a “founding member” of the myokine class of proteins. Skeletal muscle is an important source of circulating IL-6 in people who participate in exercise training. IL-6 acts as an anti-inflammatory myokine by inhibiting TNFα and improving glucose uptake through the stimulation of AMPK signaling. This review discusses the action of IL-6 in skeletal muscle tissue dysfunction and the role of IL-6 as an “exercise factor” that modulates the immune system. This review also sheds light on the main considerations related to the treatment of muscle wasting in cancer cachexia.

High-Fat Meal–Induced Changes in Markers of Inflammation and Angiogenesis in Healthy Adults Who Differ by Age and Physical Activity Level

Background

Inflammation and angiogenesis are key facets of cardiovascular disease pathophysiology. Age and physical activity level can influence fasting systemic inflammation, but the impact of these factors on postprandial inflammation is unknown. In addition, markers of angiogenesis have never been tested in the context of a single high-fat meal (HFM).

Objective

The purpose of this study was to investigate the effects of an HFM on markers of inflammation and angiogenesis in individuals of different ages and physical activity levels.

Methods

Twenty-two healthy adults—8 younger active (YA) adults (4 men, 4 women; mean ± SD age: 25 ± 5 y), 8 older active (OA) adults (4 men, 4 women; 67 ± 5 y), and 6 older inactive (OI) adults (3 men, 3 women; 68 ± 7 y)—consumed an HFM [63% fat (39% saturated fat, 14% monounsaturated fat, 10% polyunsaturated fat), 34% carbohydrate; 12 kcal/kg body mass; 927 ± 154 kcal]. Fourteen inflammatory and 9 angiogenic markers were measured at baseline and 3 and 6 h postmeal.

Results

Significant group effects were observed in interleukin (IL)-10 (YA > OA; P = 0.02), IL-23 (YA > OA; P = 0.02), tumor necrosis factor (TNF)-α (OA < OI; P = 0.04), and vascular endothelial growth factor (VEGF)-C (YA < OA; P = 0.001). IL-8, VEGF-A, VEGF-C, and heparin-binding epidermal growth factor–like growth factor significantly increased, whereas granulocyte-macrophage colony-stimulating factor, interferon-γ, IL-1β, IL-5, IL-10, IL-12, IL-13, IL-17A, IL-23, TNF-α, leptin, angiopoietin-2, and follistatin significantly decreased after HFM consumption (P’s < 0.05). Notably, VEGF-A and VEGF-C were significantly higher at 3 h [mean difference: 22.5 pg/mL (VEGF-A); 73.5 pg/mL (VEGF-C)] and 6 h postmeal [mean difference: 26.9 pg/mL (VEGF-A); 81.2 pg/mL (VEGF-C)].

Conclusions

A novel finding of this study was the robust increase in VEGF after an HFM. There were also group differences in several inflammatory markers (IL-10 and IL-23 greater in YA than OA, and TNF-α lower in OA than OI) that suggest a potential influence of age and physical activity level.

Novel mechanisms of Collagenase Santyl Ointment (CSO) in wound macrophage polarization and resolution of wound inflammation

Collagenases are useful in enzymatic wound debridement. Clostridial collagenase, marketed as Collagenase Santyl Ointment (CSO), is FDA approved for such use. Building on the scientific premise that collagenases as well as collagen degradation products may regulate immune cell function, we sought to investigate the potential role of CSO in wound inflammation. We tested the hypothesis that in addition to enacting debridement, CSO contributes to the resolution of persistent wound inflammation. Wound macrophages were isolated from PVA sponges loaded with CSO or petrolatum and implanted in mice. Significant increase in pro-reparative and decrease in pro-inflammatory polarization was noted in macrophages of acute as well as diabetic wounds. Wound macrophages from CSO-treated group displayed increased production of anti-inflammatory cytokines IL-10 and TGF-β, and decreased levels of pro-inflammatory cytokines TNF-α and IL-1β. The active ingredient of CSO, CS-API, induced the expression of mϕ^heal /M(IL-4) polarization markers ex vivo. CS-API treatment attenuated transactivation of NF-κB and significantly induced STAT6 phosphorylation. A significant role of a novel PGE2-EP4 pathway in CS-API induced STAT6 activation and the mϕ^heal /M(IL-4) polarization was identified. Taken together, findings of this work reposition CSO as a potential agent that may be effective in resolving wound inflammation, including diabetic wounds.

Resistance exercise attenuates skeletal muscle oxidative stress, systemic pro-inflammatory state, and cachexia in Walker-256 tumor-bearing rats

The aim of this study was to investigate the effects of resistance exercise training (RET) on oxidative stress, systemic inflammatory markers, and muscle wasting in Walker-256 tumor-bearing rats. Male (Wistar) rats were divided into 4 groups: sedentary controls (n = 9), tumor-bearing (n = 9), exercised (n = 9), and tumor-bearing exercised (n = 10). Exercised and tumor-bearing exercised rats were exposed to resistance exercise of climbing a ladder apparatus with weights tied to their tails for 6 weeks. The physical activity of control and tumor-bearing rats was confined to the space of the cage. After this period, tumor-bearing and tumor-bearing exercised animals were inoculated subcutaneously with Walker-256 tumor cells (11.0 × 10⁷ cells in 0.5 mL of phosphate-buffered saline) while control and exercised rats were injected with vehicle. Following inoculation, rats maintained resistance exercise training (exercised and tumor-bearing exercised) or sedentary behavior (control and tumor-bearing) for 12 more days, after which they were euthanized. Results showed muscle wasting in the tumor-bearing group, with body weight loss, increased systemic leukocytes, and inflammatory interleukins as well as muscular oxidative stress and reduced mTOR signaling. In contrast, RET in the tumor-bearing exercised group was able to mitigate the reduced body weight and muscle wasting with the attenuation of muscle oxidative stress and systemic inflammatory markers. RET also prevented loss of muscle strength associated with tumor development. RET, however, did not prevent the muscle proteolysis signaling via FBXO32 gene messenger RNA expression in the tumor-bearing group. In conclusion, RET performed prior tumor implantation prevents cachexia development by attenuating tumor-induced systemic pro-inflammatory condition with muscle oxidative stress and muscle damage.

Postprandial lipemic and inflammatory responses to high-fat meals: a review of the roles of acute and chronic exercise

Postprandial lipemia is an independent risk factor for development of cardiovascular disease. Postprandial inflammation following the prolonged elevation of triglycerides occurring subsequent to ingestion of high-fat meals, provides a likely explanation for increased disease risk. Substantial evidence has shown that acute exercise is an effective modality for attenuation of postprandial lipemia following a high-fat meal. However, much of the evidence pertaining to exercise intensity, duration, and overall energy expenditure for reducing postprandial lipemia is inconsistent. The effects of these different exercise variables on postprandial inflammation is largely unknown. Long-term, frequent exercise, however, appears to effectively reduce systemic inflammation, especially in at-risk or diseased individuals. With regard to an acute postprandial response, without a recent bout of exercise, high levels of chronic exercise do not appear to reduce postprandial lipemia. This review summarizes the current literature on postprandial and inflammatory responses to high-fat meals, and the roles that both acute and chronic exercise play. This review may be valuable for health professionals who wish to provide evidence-based, pragmatic advice for reducing postprandial lipemia and cardiovascular disease risk for their patients. A brief review of proposed mechanisms explaining how high-fat meals may result in pro-inflammatory and pro-atherosclerotic environments is also included.

Modeling and Hemofiltration Treatment of Acute Inflammation

The body responds to endotoxins by triggering the acute inflammatory response system to eliminate the threat posed by gram-negative bacteria (endotoxin) and restore health. However, an uncontrolled inflammatory response can lead to tissue damage, organ failure, and ultimately death; this is clinically known as sepsis. Mathematical models of acute inflammatory disease have the potential to guide treatment decisions in critically ill patients. In this work, an 8-state (8-D) differential equation model of the acute inflammatory response system to endotoxin challenge was developed. Endotoxin challenges at 3 and 12 mg/kg were administered to rats, and dynamic cytokine data for interleukin (IL)-6, tumor necrosis factor (TNF), and IL-10 were obtained and used to calibrate the model. Evaluation of competing model structures was performed by analyzing model predictions at 3, 6, and 12 mg/kg endotoxin challenges with respect to experimental data from rats. Subsequently, a model predictive control (MPC) algorithm was synthesized to control a hemoadsorption (HA) device, a blood purification treatment for acute inflammation. A particle filter (PF) algorithm was implemented to estimate the full state vector of the endotoxemic rat based on time series cytokine measurements. Treatment simulations show that: (i) the apparent primary mechanism of HA efficacy is white blood cell (WBC) capture, with cytokine capture a secondary benefit; and (ii) differential filtering of cytokines and WBC does not provide substantial improvement in treatment outcomes vs. existing HA devices.

Impact of mechanical stretch on the cell behaviors of bone and surrounding tissues

Mechanical loading is recognized to play an important role in regulating the behaviors of cells in bone and surrounding tissues in vivo. Many in vitro studies have been conducted to determine the effects of mechanical loading on individual cell types of the tissues. In this review, we focus specifically on the use of the Flexercell system as a tool for studying cellular responses to mechanical stretch. We assess the literature describing the impact of mechanical stretch on different cell types from bone, muscle, tendon, ligament, and cartilage, describing individual cell phenotype responses. In addition, we review evidence regarding the mechanotransduction pathways that are activated to potentiate these phenotype responses in different cell populations.

Exercise ameliorates high fat diet induced cardiac dysfunction by increasing interleukin 10

Increasing evidence suggests that a sedentary lifestyle and a high fat diet (HFD) leads to cardiomyopathy. Moderate exercise ameliorates cardiac dysfunction, however underlying molecular mechanisms are poorly understood. Increased inflammation due to induction of pro-inflammatory cytokine such as tumor necrosis factor-alpha (TNF-α) and attenuation of anti-inflammatory cytokine such as interleukin 10 (IL-10) contributes to cardiac dysfunction in obese and diabetics. We hypothesized that exercise training ameliorates HFD- induced cardiac dysfunction by mitigating obesity and inflammation through upregulation of IL-10 and downregulation of TNF-α. To test this hypothesis, 8 week old, female C57BL/6J mice were fed with HFD and exercised (swimming 1 h/day for 5 days/week for 8 weeks). The four treatment groups: normal diet (ND), HFD, HFD + exercise (HFD + Ex) and ND + Ex were analyzed for mean body weight, blood glucose level, TNF-α, IL-10, cardiac fibrosis by Masson Trichrome, and cardiac dysfunction by echocardiography. Mean body weights were increased in HFD but comparatively less in HFD + Ex. The level of TNF-α was elevated and IL-10 was downregulated in HFD but ameliorated in HFD + Ex. Cardiac fibrosis increased in HFD and was attenuated by exercise in the HFD + Ex group. The percentage ejection fraction and fractional shortening were decreased in HFD but comparatively increased in HFD + Ex. There was no difference between ND and ND + Ex for the above parameters except an increase in IL-10 level following exercise. Based on these results, we conclude that exercise mitigates HFD- induced cardiomyopathy by decreasing obesity, inducing IL-10, and reducing TNF-α in mice.

Suppression of dust mite allergy by mucosal delivery of a hypoallergenic derivative in a mouse model

Allergic asthma caused by house dust mite (HDM) is becoming a public health problem. Specific immunotherapy is considered to be the only curative treatment, but it is always associated with IgE-mediated side effects in the therapy process. A few studies showed that the disruption of allergen IgE epitopes could reduce IgE reactivity and thus reduce allergenic activity. In this study, a hypoallergenic derivative of the major HDM allergen Der p2 was constructed by genetic engineering. This derivative was confirmed to have a considerably reduced IgE reactivity compared with Der p2. For its application in vivo, recombinant Lactococcus lactis (LL-DM) was engineered to deliver the Der p2 derivative to the intestinal mucosal surface. Oral administration of LL-DM significantly alleviated Der p2-induced airway inflammation, as shown by reduced inflammatory infiltration and a reduction in Th2 cytokines in bronchoalveolar lavage. This protective effect was associated with an up-regulation of specific IgG2a and a decrease in IL-4 level in the spleen which may affect specific IgE response. Moreover, the levels of regulatory T cells in the mesenteric lymph nodes and spleen were markedly increased in mice fed with LL-DM, suggesting that LL-DM can inhibit allergic responses via the induction of regulatory T cell. Our results indicate that the Der p2 derivative is a promising therapeutic molecule for specific immunotherapy and recombinant lactic acid bacteria could be developed as a promising treatment or prevention strategy for allergic diseases.

Genetically engineered Lactococcus lactis protect against house dust mite allergy in a BALB/c mouse model

Background

Mucosal vaccine based on lactic acid bacteria is an attractive concept for the prevention and treatment of allergic diseases, but their mechanisms of action in vivo are poorly understood. Therefore, we sought to investigate how recombinant major dust mite allergen Der p2-expressing Lactococcus lactis as a mucosal vaccine induced the immune tolerance against house dust mite allergy in a mouse model.

Methods

Three strains of recombinant L. lactis producing Der p2 in different cell components (extracellular, intracellular and cell wall) were firstly constructed. Their prophylactic potential was evaluated in a Der p2-sensitised mouse model, and immunomodulation properties at the cellular level were determined by measuring cytokine production in vitro.

Results

Der p2 expressed in the different recombinant L. lactis strains was recognized by a polyclonal anti-Der p2 antibody. Oral treatment with the recombinant L. lactis prior sensitization significantly prevented the development of airway inflammation in the Der p2-sensitized mice, as determined by the attenuation of inflammatory cells infiltration in the lung tissues and decrease of Th2 cytokines IL-4 and IL-5 levels in bronchoalveolar lavage. In addition, the serum allergen-specific IgE levels were significantly reduced, and the levels of IL-4 in the spleen and mesenteric lymph nodes cell cultures were also markedly decreased upon allergen stimulation in the mice fed with the recombinant L. lactis strains. These protective effects correlated with a significant up-regulation of regulatory T cells in the mesenteric lymph nodes.

Conclusion

Oral pretreatment with live recombinant L. lactis prevented the development of allergen-induced airway inflammation primarily by the induction of specific mucosal immune tolerance.

Beneficial Effects of Citrus Juice Fermented with Lactobacillus plantarum YIT 0132 on Japanese Cedar Pollinosis

Recently, the prevalence of allergies in Japan has been increasing. Certain types of fruit juice and lactic acid bacteria are known to alleviate allergic symptoms. Therefore, we examined whether citrus juice fermented by a specific lactic acid bacteria can improve the symptoms of Japanese cedar pollinosis (JCPsis). Lactobacillus plantarum YIT 0132 (LP0132) was selected based on its high proliferative activity in citrus juice and anti-inflammatory interleukin-10-inducing activity. Dietary administration of heat-killed LP0132 cells or citrus juice fermented with LP0132 was found to significantly suppress nasal rubbing in a JCPsis mouse model, indicating relief of allergy symptoms. To evaluate the effects of LP0132-fermented citrus juice on pollinosis symptoms and quality of life (QOL) in humans with JCPsis, a single-blind, placebo-controlled, parallel-group clinical trial was conducted. The participants were 42 adults with JCPsis. They ingested 100 mL of sterilized LP0132-fermented citrus juice (active group) or unfermented citrus juice (placebo group) once daily for 8 weeks. Immediately after the pollen peak when allergy symptoms and QOL loss were most severe, itchy eyes, itchy skin, and QOL loss by JCPsis were alleviated in the active group compared with the placebo group. At 10 weeks after starting the intervention, increased the levels of blood eosinophils were significantly suppressed in the active group compared with the placebo group. We conclude that continuous ingestion of citrus juice fermented with LP0132 may help alleviate the allergy symptoms and impaired QOL caused by JCPsis.

Role of exercise training on autonomic changes and inflammatory profile induced by myocardial infarction

The cardiovascular autonomic imbalance in patients after myocardial infarction (MI) provides a significant increase in mortality rate, and seems to precede metabolic, hormonal, and immunological changes. Moreover, the reduction in the parasympathetic function has been associated with inflammatory response in different pathological conditions. Over the years, most of the studies have indicated the exercise training (ET) as an important nonpharmacological tool in the management of autonomic dysfunction and reduction in inflammatory profile after a myocardial infarction. In this work, we reviewed the effects of ET on autonomic imbalance after MI, and its consequences, particularly, in the post-MI inflammatory profile. Clinical and experimental evidence regarding relationship between alterations in autonomic regulation and local or systemic inflammation response after MI were also discussed.

Bovine colostrum, training status, and gastrointestinal permeability during exercise in the heat: a placebo-controlled double-blind study

Heat stress can increase gastrointestinal permeability, allowing ingress of gram-negative bacterial fragments and thus potentially inflammation and ultimately endotoxemia. Permeability may rise with intense exercise, yet some data indicate that endotoxemia may be mitigated with bovine colostrum supplementation. Using a double-blind, randomised, placebo-controlled crossover study, we tested whether bovine colostrum (COL; 1.7 g·kg(-1)·day(-1) for 7 days) would attenuate physiological strain and aid exercise capacity in the heat, especially in untrained individuals. Seven trained men (T; peak oxygen uptake 64 ± 4 mL·kg(-1)·min(-1)) and 8 untrained men (UT, peak oxygen uptake 46 ± 4 mL·kg(-1)·min(-1)) exercised for 90 min in 30 °C (50 % relative humidity) after COL or placebo (corn flour). Exercise consisted of 15-min cycling at 50 % heart rate reserve (HRR) before and after 60 min of running (30 min at 80 % HRR then 30-min distance trial). Heart rate, blood pressure (Finometer), esophageal, and skin temperatures were recorded continuously. Gastrointestinal permeability was assessed from urine (double-sugar model, using high-performance liquid chromatography) and blood (intestinal fatty acid-binding protein, I-FABP). The T group ran ∼2.4 km (35%) further than the UT group in the distance trial, and I-FABP increased more in the T group than in the UT group, but physiological and performance outcomes were unaffected by colostrum supplementation, irrespective of fitness. Circulating pro- and anti-inflammatory cytokine concentrations were higher following exercise, but were not modulated by fitness or COL. Despite substantial thermal and cardiovascular strain incurred in environmental conditions in which exertional endotoxemia may occur, bovine colostrum supplementation had no observable benefit on the physiology or performance of either highly trained endurance athletes or untrained individuals.

Engulfment of apoptotic cells by macrophages: a role of microRNA-21 in the resolution of wound inflammation

At an injury site, efficient clearance of apoptotic cells by wound macrophages or efferocytosis is a prerequisite for the timely resolution of inflammation. Emerging evidence indicates that microRNA-21 (miR-21) may regulate the inflammatory response. In this work, we sought to elucidate the significance of miR-21 in the regulation of efferocytosis-mediated suppression of innate immune response, a key process implicated in resolving inflammation following injury. An increased expression of inducible miR-21 was noted in postefferocytotic peripheral blood monocyte-derived macrophages. Such induction of miR-21 was associated with silencing of its target genes PTEN and PDCD4. Successful efferocytosis of apoptotic cells by monocyte-derived macrophages resulted in the suppression of LPS-induced NF-κB activation and TNF-α expression. Interestingly, bolstering of miR-21 levels alone, using miR mimic, resulted in significant suppression of LPS-induced TNF-α expression and NF-κB activation. We report that efferocytosis-induced miR-21, by silencing PTEN and GSK3β, tempers the LPS-induced inflammatory response. Macrophage efferocytosis is known to trigger the release of anti-inflammatory cytokine IL-10. This study demonstrates that following successful efferocytosis, miR-21 induction in macrophages silences PDCD4, favoring c-Jun-AP-1 activity, which in turn results in elevated production of anti-inflammatory IL-10. In summary, this work provides direct evidence implicating miRNA in the process of turning on an anti-inflammatory phenotype in the postefferocytotic macrophage. Elevated macrophage miR-21 promotes efferocytosis and silences target genes PTEN and PDCD4, which in turn accounts for a net anti-inflammatory phenotype. Findings of this study highlight the significance of miRs in the resolution of wound inflammation.

IL-10 gene polymorphisms and their association with immune traits in four rabbit populations

Interleukin-10 (IL-10) has been recently identified as a multifunctional cytokine, because of its close link with immunoregulation and anti-inflammatory responses. This study investigated the association of IL-10 genetic polymorphisms with the immune traits of New Zealand white rabbits (N-W), Fujian yellow rabbits (F-Y) and their reciprocal crosses (N-Y and Y-N, respectively). SNPs on five exons of the IL-10 gene were genotyped in 204 healthy rabbits via PCR-SSCP and DNA sequencing. Two SNPs (A1435G and G1519A, both were synonymous mutations) and six genotypes (AA, BB, CC, AB, AC and BC) were found on exon 3 and one SNP (T base insertion between loci 2532 and 2533, which caused a frameshift mutation), and three genotypes (OO, TT and TO) were present on exon 4. Allele A was the most frequent allele on exon 3 (from 0.548 to 0.771), whereas O was the most frequent on exon 4 (from 0.808 to 0.968). These four populations were all in Hardy-Weinberg equilibrium on both exon3 and exon4. Association analysis between polymorphisms and immune parameters showed that SNPs on exon 3 were significantly associated with immune traits, while SNP on exon 4 may not significantly affect immune traits, but the mechanism is yet to be further studied.

Cancer cachexia prevention via physical exercise: molecular mechanisms

Cancer cachexia is a debilitating consequence of disease progression, characterised by the significant weight loss through the catabolism of both skeletal muscle and adipose tissue, leading to a reduced mobility and muscle function, fatigue, impaired quality of life and ultimately death occurring with 25-30 % total body weight loss. Degradation of proteins and decreased protein synthesis contributes to catabolism of skeletal muscle, while the loss of adipose tissue results mainly from enhanced lipolysis. These mechanisms appear to be at least, in part, mediated by systemic inflammation. Exercise, by virtue of its anti-inflammatory effect, is shown to be effective at counteracting the muscle catabolism by increasing protein synthesis and reducing protein degradation, thus successfully improving muscle strength, physical function and quality of life in patients with non-cancer-related cachexia. Therefore, by implementing appropriate exercise interventions upon diagnosis and at various stages of treatment, it may be possible to reverse protein degradation, while increasing protein synthesis and lean body mass, thus counteracting the wasting seen in cachexia.

Effect of exercise on chemically-induced colitis in adiponectin deficient mice

Background

Inflammatory bowel diseases are associated with increased adiponectin (APN) levels, which may exert pro-inflammatory effects in these individuals. Since habitual exercise may increase APN, the aim of this study was to determine how exercise training affects mice with acute colitis.

Methods

Male adiponectin knock out (APNKO) and wild type (WT) mice (C57BL/6) were randomly assigned to 4 different groups: 1) Sedentary (SED); 2) Exercise trained (ET); 3) Sedentary with dextran sodium sulfate (DSS) treatment (SED + DSS); and 4) Exercise trained with DSS (ET + DSS). Exercise-trained mice ran at 18 m/min for 60 min, 5d/wk for 4 weeks. Subsequently, the ET + DSS and the SED + DSS mice received 2% DSS in their drinking water for 5 days (d), followed by 5d of regular water.

Results

The clinical symptoms of acute colitis (diarrhea, stool haemoccult, and weight loss) were unaffected by exercise and there was no difference between the APNKO and WT mice (p > 0.05) except on day 39. However, the clinical symptoms of the DSS-treated APNKO mice were worse than WT mice treated with DSS and had increased susceptibility to intestinal inflammation due to increased local STAT3 activation, higher IL-6, TNF-α, IL-1β and IL-10 levels, and as a result had increased intestinal epithelial cell proliferation (p < 0.05). Exercise training significantly decreased pro-inflammatory cytokines including IL-6, TNF-α and IL-1β (p < 0.05) in the DSS + EX APNKO mice but had no effect on epithelial cell proliferation. Exercise was also found to significantly decrease the phosphorylation expression of STAT3 in both WT and APNKO mice in DSS + EX group when compared to DSS + SED.

Conclusions

Exercise training may contribute in alleviating the symptoms of acute colitis and APN deficiency may exacerbate the intestinal inflammation in DSS-induced colitis.

Construction of a Der p2-transgenic plant for the alleviation of airway inflammation

In clinical therapy, the amount of antigen administered to achieve oral tolerance for allergic diseases is large, and the cost is a major consideration. In this study, we used tobacco plants to develop a large-scale protein production system for allergen-specific immunotherapy, and we investigated the mechanisms of oral tolerance induced by a transgenic plant-derived antigen. We used plants (tobacco leaves) transgenic for the Dermatophagoides pteronyssinus 2 (Der p2) antigen to produce Der p2. Mice received total protein extract from Der p2 orally once per day over 6 days (days 0-2 and days 6-8). Mice were also sensitized and challenged with yeast-derived recombinant Der p2 (rDer p2), after which the mice were examined for airway hyper-responsiveness and airway inflammation. After sensitization and challenge with rDer p2, mice that were fed with total protein extracted from transgenic plants showed decreases in serum Der p2-specific IgE and IgG1 titers, decreased IL-5 and eotaxin levels in bronchial alveolar lavage fluid, and eosinophil infiltration in the airway. In addition, hyper-responsiveness was also decreased in mice that were fed with total protein extracted from transgenic plants, and CD4(+)CD25(+)Foxp3(+) regulatory T cells were significantly increased in mediastinal and mesenteric lymph nodes. Furthermore, splenocytes isolated from transgenic plant protein-fed mice exhibited decreased proliferation and increased IL-10 secretion after stimulation with rDer p2. The data here suggest that allergen-expressing transgenic plants could be used for therapeutic purposes for allergic diseases.

Interleukin-10 and -12 predict chemotherapy-associated toxicity in esophageal adenocarcinoma

INTRODUCTION

Chemotherapy-associated mucositis often prevents completion of an entire chemotherapy cycle. The underlying pathophysiology of chemotherapy-associated mucositis has not been well established. The individual immunologic predisposition of patients seems to play an important role.

METHODS

One hundred fifty-six patients with locally advanced or metastatic esophageal adenocarcinoma received neoadjuvant chemotherapy with cisplatin, 5-fluorouracil, and leucovorin followed by resection. Before the neoadjuvant therapy, monocytes were isolated from blood samples and were stimulated with lipopolysaccharide and interferon. An enzyme-linked immunosorbent assay was used to measure interleukin (IL)-10 and -12 levels and correlated with patients' clinical course.

RESULTS

Twenty-two patients (14,1%) developed grade III to IV mucositis (according to the NCI-Common toxicity criteria scales) within the neoadjuvant chemotherapy. Pretherapeutic low IL-10 (<24.1 pg/ml) and high IL-12 (>5500 pg/ml) levels were significantly associated with mucositis causing a therapy interruption or even cessation. Patients with high IL-10 (>43.6 pg/ml) and low IL-12 (<4408.5 pg/ml) levels had an uneventful neoadjuvant chemotherapy.

CONCLUSIONS

Pretherapeutic individual monocyte function is correlated with the development and the grade of chemotherapy induced mucositis. This knowledge might help us in predicting the grade of mucositis and in understanding the genesis regarding the association to pro- and anti-inflammatory effects of monocyte cytokines.

Chronic low frequency/low volume resistance training reduces pro-inflammatory cytokine protein levels and TLR4 mRNA in rat skeletal muscle

Skeletal muscle is the source of pro- and anti-inflammatory cytokines, and recently, it has been recognized as an important source of interleukin 6 (IL-6), a cytokine that exerts inhibitory effects on several pro-inflammatory cytokines. Although dynamic chronic resistance training has been shown to produce the known "repeated bout effect", which abolishes the acute muscle damage, performing of high-intensity resistance training has been regarded highly advisable, at least from the hypertrophy perspective. On the other hand, a more therapeutic, "non-damaging" resistance training program, mainly composed of concentric forces, low frequency/low volume of training, and the same exercise, could theoretically benefit the muscle when the main issue is to avoid muscle inflammation (as in the treatment of several "low-grade" inflammatory diseases) because the acute effect of each resistance exercise session could be diminished/avoided, at the same time that the muscle is still being overloaded in a concentric manner. However, the benefits of such "less demanding" resistance training schedule on the muscle inflammatory profile have never been investigated. Therefore, we assessed the protein expression of IL-6, TNF-alpha, IL-10, IL-10/TNF-alpha ratio, and HSP70 levels and mRNA expression of SCF(beta-TrCP), IL-15, and TLR-4 in the skeletal muscle of rats submitted to resistance training. Briefly, animals were randomly assigned to either a control group (S, n = 8) or a resistance-trained group (T, n = 7). Trained rats were exercised over a duration of 12 weeks (two times per day, two times per week). Detection of IL-6, TNF-alpha, IL-10, and HSP70 protein expression was carried out by western blotting and SCF(beta-TrCP) (SKP Cullin F-Box Protein Ligases), a class of enzymes involved in the ubiquitination of protein substrates to proteasomal degradation, IL-15, and TLR-4 by RT-PCR. Our results show a decreased expression of TNF-alpha and TLR4 mRNA (40 and 60%, respectively; p < 0.05) in the plantar muscle from trained, when compared with control rats. In conclusion, exercise training induced decreased TNF-alpha and TLR-4 expressions, resulting in a modified IL-10/TNF-alpha ratio in the skeletal muscle. These data show that, in healthy rats, 12-week resistance training, predominantly composed of concentric stimuli and low frequency/low volume schedule, down regulates skeletal muscle production of cytokines involved in the onset, maintenance, and regulation of inflammation.

Calories and carcinogenesis: lessons learned from 30 years of calorie restriction research

Calorie restriction (CR) is arguably the most potent, broadly acting dietary regimen for suppressing the carcinogenesis process, and many of the key studies in this field have been published in Carcinogenesis. Translation of the knowledge gained from CR research in animal models to cancer prevention strategies in humans is urgently needed given the worldwide obesity epidemic and the established link between obesity and increased risk of many cancers. This review synthesizes the evidence on key biological mechanisms underlying many of the beneficial effects of CR, with particular emphasis on the impact of CR on growth factor signaling pathways and inflammatory processes and on the emerging development of pharmacological mimetics of CR. These approaches will facilitate the translation of CR research into effective strategies for cancer prevention in humans.

Molecular inflammation: underpinnings of aging and age-related diseases

Recent scientific studies have advanced the notion of chronic inflammation as a major risk factor underlying aging and age-related diseases. In this review, low-grade, unresolved, molecular inflammation is described as an underlying mechanism of aging and age-related diseases, which may serve as a bridge between normal aging and age-related pathological processes. Accumulated data strongly suggest that continuous (chronic) upregulation of pro-inflammatory mediators (e.g., TNF-alpha, IL-1beta, IL-6, COX-2, iNOS) are induced during the aging process due to an age-related redox imbalance that activates many pro-inflammatory signaling pathways, including the NF-kappaB signaling pathway. These pro-inflammatory molecular events are discussed in relation to their role as basic mechanisms underlying aging and age-related diseases. Further, the anti-inflammatory actions of aging-retarding caloric restriction and exercise are reviewed. Thus, the purpose of this review is to describe the molecular roles of age-related physiological functional declines and the accompanying chronic diseases associated with aging. This new view on the role of molecular inflammation as a mechanism of aging and age-related pathogenesis can provide insights into potential interventions that may affect the aging process and reduce age-related diseases, thereby promoting healthy longevity.

A biobehavioral model for the study of exercise interventions in cancer-related fatigue

Cancer-related fatigue (CRF) is a multifactorial, biobehavioral phenomenon experienced by the majority of persons with cancer. It has negative consequences on the individual's physical functioning and quality of life. An array of biological, psychobehavioral, and functional mechanisms contributes to its occurrence. A relatively large number of studies have examined the effect of physical exercise on CRF over the past few decades. Most of these studies did not specifically examine the effect of physical exercise on the biobehavioral mechanisms underlying CRF. For the most part, these studies have not been guided by a consistent theoretical model. Consequently, the mechanisms by which exercise may ameliorate CRF are not fully elucidated. A theoretical model incorporating fatigue-related biobehavioral variables that could be affected by physical exercise will allow for effective knowledge development in this area and could lead to the development and refinement of exercise protocols that specifically target these mechanisms. Thus, the purpose of this paper is to present a comprehensive theoretical model to guide future research on the effectiveness of exercise interventions in CRF. The proposed model incorporates the biological, psychobehavioral, and functional variables implicated in the induction of CRF.

The biological mechanisms of cancer-related skeletal muscle wasting: the role of progressive resistance exercise

Cancer results in perturbations in skeletal muscle protein metabolism leading to muscle wasting. Although severe wasting is seen primarily in persons with advanced malignancies, a number of cancer patients show some degree of wasting at presentation. Although cancer-related skeletal muscle wasting is attributable, in part, to decreased muscle protein synthesis, its primary cause appears to be increased muscle protein degradation. Although several proteolytic systems may be involved, compelling evidence suggests that the major system responsible for skeletal muscle protein degradation in cancer is the ATP-dependent ubiquitin- proteasome system. Other contributing factors include proinflammatory cytokines and the tumor-released proteolysis-inducing factor. Decreased physical activity and decreased nutritional intake may also play a role. Cancer-related skeletal muscle wasting is clinically significant because of its profound effects on functional outcomes and quality of life. Nevertheless, no specific interventions have proved to be effective in preventing or reversing the problem. Interventions such as nutritional supplementation and appetite stimulants are only partially helpful. A nonpharmacologic intervention that may attenuate cancer-related skeletal muscle wasting is progressive resistance exercise training (PRT). PRT is a potent stimulus of growth in muscle mass and strength. PRT may attenuate cancer-related skeletal muscle wasting by downregulating the activity of proinflammatory cytokines and by increasing the phosphorylation of intramuscular amino acid-signaling molecules. This article discusses several cancer-related skeletal muscle wasting mechanisms and proposes how PRT might attenuate muscle wasting by counteracting some of these mechanisms.

Reducing the weight of cancer: mechanistic targets for breaking the obesity-carcinogenesis link

The prevalence of obesity, an established epidemiologic risk factor for many cancers, has risen steadily for the past several decades in the US. The increasing rates of obesity among children are especially alarming and suggest continuing increases in the rates of obesity-related cancers for many years to come. Unfortunately, the mechanisms underlying the association between obesity and cancer are not well understood. In particular, the effects on the carcinogenesis process and mechanistic targets of interventions that modulate energy balance, such as reduced-calorie diets and physical activity, have not been well characterized. The purpose of this review is to provide a strong foundation for the translation of mechanism-based research in this area by describing key animal and human studies of energy balance modulations involving diet or physical activity and by focusing on the interrelated pathways affected by alterations in energy balance. Particular attention is placed on signaling through the insulin and insulin-like growth factor-1 receptors, including components of the Akt and mammalian target of rapamycin (mTOR) signaling pathways downstream of these growth factor receptors. These pathways have emerged as potential targets for disrupting the obesity-cancer link. The ultimate goal of this work is to provide the missing mechanistic information necessary to identify targets for the prevention and control of cancers related to or caused by excess body weight.

Physical activity and cancer prevention : pathways and targets for intervention

The prevalence of obesity, an established epidemiological risk factor for many cancers, has risen steadily for the past several decades in the US and many other countries. Particularly alarming are the increasing rates of obesity among children, portending continuing increases in the rates of obesity and obesity-related cancers for many years to come. Modulation of energy balance, via increased physical activity, has been shown in numerous comprehensive epidemiological reviews to reduce cancer risk. Unfortunately, the effects and mechanistic targets of physical activity interventions on the carcinogenesis process have not been thoroughly characterized. Studies to date suggest that exercise can exert its cancer-preventive effects at many stages during the process of carcinogenesis, including both tumour initiation and progression. As discussed in this review, exercise may be altering tumour initiation events by modifying carcinogen activation, specifically by enhancing the cytochrome P450 system and by enhancing selective enzymes in the carcinogen detoxification pathway, including, but not limited to, glutathione-S-transferases. Furthermore, exercise may reduce oxidative damage by increasing a variety of anti-oxidant enzymes, enhancing DNA repair systems and improving intracellular protein repair systems. In addition to altering processes related to tumour initiation, exercise may also exert a cancer-preventive effect by dampening the processes involved in the promotion and progression stages of carcinogenesis, including scavenging reactive oxygen species (ROS); altering cell proliferation, apoptosis and differentiation; decreasing inflammation; enhancing immune function; and suppressing angiogenesis. A paucity of data exists as to whether exercise may be working as an anti-promotion strategy via altering ROS in initiated or preneoplastic models; therefore, no conclusions can be made about this possible mechanism. The studies directly examining cell proliferation and apoptosis have shown that exercise can enhance both processes, which is difficult to interpret in the context of carcinogenesis. Studies examining the relationship between exercise and chronic inflammation suggest that exercise may reduce pro-inflammatory mediators and reduce the state of low-grade, chronic inflammation. Additionally, exercise has been shown to enhance components of the innate immune response (i.e. macrophage and natural killer cell function). Finally, only a limited number of studies have explored the relationship between exercise and angiogenesis; therefore, no conclusions can be made currently about the role of exercise in the angiogenesis process as it relates to tumour progression. In summary, exercise can alter biological processes that contribute to both anti-initiation and anti-progression events in the carcinogenesis process. However, more sophisticated, detailed studies are needed to examine each of the potential mechanisms contributing to an exercise-induced decrease in carcinogenesis in order to determine the minimum dose, duration and frequency of exercise needed to yield significant cancer-preventive effects, and whether exercise can be used prescriptively to reverse the obesity-induced physiological changes that increase cancer risk.

Inflammation in chronic heart failure

OBJECTIVE

To summarize findings regarding the association of inflammatory processes with chronic heart failure (HF).

DATA SOURCES

We conducted PubMed/MEDLINE searches (1966-January 2008) of primary literature using the following key words: ACE inhibitors, allopurinol, angiotensin-receptor antagonists, cardiomyopathy, chemokines, cytokines, diuretics, heart failure, inflammation, interleukins, HMG-CoA reductase inhibitors, immunotherapy, medications used in heart failure, thalidomide, tumor necrosis factor, and uric acid.

STUDY SELECTION AND DATA EXTRACTION

All articles that appeared to be relevant were read; of 305 articles examined, 87 were selected for discussion. Articles were selected if they were written in English and focused on any of the key words or appeared to have substantial content addressing inflammation in HF.

DATA SYNTHESIS

Cytokines, uric acid, and other inflammatory mediators are associated with physiologic effects that are also prominent features of HF (eg, reduced contractility and cardiac output, endothelial dysfunction, hypercoagulability, autonomic dysfunction as evidenced by reduced resting heart rate variability, insulin resistance). With the exception of elevated tumor necrosis factor-alpha as a cause of insulin resistance, it is not clear whether elevated inflammatory mediators directly cause HF signs and symptoms or whether they are incidental markers. Awareness of these associations has occurred relatively recently; there have been few clinical studies of efforts to directly modify inflammatory mediators. Most currently accepted drug therapies of HF reduce concentrations of circulating cytokines, but the significance of these findings awaits directed study.

CONCLUSIONS

Loss of myocardial function, autonomic dysfunction, and glucose intolerance are interrelated and linked by underlying chronic low-grade inflammation. Drug therapy with statins, pentoxifylline, and perhaps urate-lowering agents, in addition to current therapies, holds promise for treatment of HF.

An ensemble of models of the acute inflammatory response to bacterial lipopolysaccharide in rats: results from parameter space reduction

In previous work, we developed an 8-state nonlinear dynamic model of the acute inflammatory response, including activated phagocytic cells, pro- and anti-inflammatory cytokines, and tissue damage, and calibrated it to data on cytokines from endotoxemic rats. In the interest of parsimony, the present work employed parametric sensitivity and local identifiability analysis to establish a core set of parameters predominantly responsible for variability in model solutions. Parameter optimization, facilitated by varying only those parameters belonging to this core set, was used to identify an ensemble of parameter vectors, each representing an acceptable local optimum in terms of fit to experimental data. Individual models within this ensemble, characterized by their different parameter values, showed similar cytokine but diverse tissue damage behavior. A cluster analysis of the ensemble of models showed the existence of a continuum of acceptable models, characterized by compensatory mechanisms and parameter changes. We calculated the direct correlations between the core set of model parameters and identified three mechanisms responsible for the conversion of the diverse damage time courses to similar cytokine behavior in these models. Given that tissue damage level could be an indicator of the likelihood of mortality, our findings suggest that similar cytokine dynamics could be associated with very different mortality outcomes, depending on the balance of certain inflammatory elements.

Effects of Insulin on Hepatic Inflammation Induced by Ethanol and Burn Injury in a Murine Model of Critical Illness

In recent, landmark clinical trials, insulin to maintain euglycemia in critically ill patients improved clinical outcomes, including decreased all-cause mortality. Novel antiinflammatory effects of insulin have recently been described. Thermal injury is an excellent model of critical illness. The addition of ethanol to the model is of great clinical relevance because nearly 50% of the patients admitted to hospitals for burn injuries have ethanol in their circulation. Utilizing a murine model of critical illness (ethanol and skin burn), we tested the hypothesis that insulin treatment in ethanol-exposed, burn-injured mice reduced hepatic inflammation, a potential mechanism for the benefit of insulin. Adult male C57BL/6 mice were given a single intraperitoneal injection of ethanol or saline, were given a 15% total body full-thickness skin burn, or were sham-burned and killed 24 hours later. In each group, half the animals were given subcutaneous injections of the long-lasting basal insulin glargine; the other half, the appropriate vehicle. Hepatic inflammatory markers, including polymorphonuclear infiltration, a chemokine, an important adhesion molecule, proinflammatory cytokines, and nuclear factor kappaB, were measured, and all were increased by ethanol and/or burn. These increases were prevented by insulin. An antiinflammatory cytokine was reduced by ethanol and/or burn. Insulin prevented this decrease. Thus, insulin has a substantial antiinflammatory effect, and this may underlie its dramatic clinical benefit in critical illness.

Chronic intermittent hypoxia modulates eosinophil- and neutrophil-platelet aggregation and inflammatory cytokine secretion caused by strenuous exercise in men

Although acclimatization to intermittent hypoxia (IH) improves exercise performance by increasing oxygen delivery and utilization, the effects of chronic IH on platelet-leukocyte interaction and inflammation-related cytokine secretion caused by strenuous exercise remain unclear. This investigation elucidates how two intensities of IH influence eosinophil- and neutrophil-platelet aggregation (EPA and NPA) as well as pro- and anti-inflammatory cytokines mediated by strenuous exercise. Twenty healthy sedentary men were randomly divided into severe (SIH) and moderate (MIH) IH groups; groups were exposed to 12% O2 (SIH) and 15% O2 (MIH) for 1 h/day, respectively, for 5 days/wk for 8 wk in a normobaric hypoxia chamber. Before IH intervention, 1) exercise up to maximal oxygen consumption promoted shear stress-, LPS-, and N-formyl-methionyl-leucyl-phenylalanine-induced EPA, increased IL-1beta and malondialdehyde levels, and decreased total antioxidant levels in plasma and 2) exposure to 12% O2, but not to 15% O2 for 1 h, enhanced LPS-induced EPA and reduced plasma total antioxidant levels. After IH for 8 wk, hypoxia- and exercise-promoted EPA, IL-1beta, or malondialdehyde levels were suppressed in both MIH and SIH groups, and plasma IL-6 and IL-10 levels in the SIH group were increased. However, the NPA induced by the shear force and chemical agonists was not changed under the two IH regimens. Therefore, both MIH and SIH regimens ameliorate eosinophil- and platelet-related thrombosis, proinflammatory IL-1beta secretion, and lipid peroxidation enhanced by strenuous exercise. Furthermore, SIH simultaneously increases circulatory anti-inflammatory IL-6 and IL-10 concentrations. These findings can help to develop effective IH regimens that improve aerobic fitness and minimize risk of thromboinflammation.

Different profiles of IL-10+IFN-gamma-IL-4-CD4+ T cells in the peripheral blood in atopic and non-atopic asthmatics

BACKGROUND

The impaired production of interleukin (IL) 10 from regulatory T cells has been proposed as a causal mechanism of asthma. Although IL-10-producing (IL-10+) T cells are detectable in the peripheral blood, their significance in the pathophysiology of asthma remains uncertain.

OBJECTIVES

This study aimed to investigate the profile of circulating IL-10+CD4+ T cells in atopic and non-atopic asthma.

METHODS

Atopic and non-atopic asthmatics were divided into a mild and severe group. Their peripheral blood mononuclear cells (PBMCs) were stimulated with anti-CD3 and anti-CD28 antibodies and then processed for triple cytokine flow cytometry directed to IL-10, interferon (IFN) gamma and IL-4.

RESULTS

IL-10+CD4+ cells were exclusively detected in the IFN-gamma-IL-4- population. In atopic asthma, the frequency of IL-10+IFN-gamma-IL-4-CD4+ cells in the severe group was significantly lower than that in the mild group. The frequency of IL-10+IFN-gamma-IL-4-CD4+ cells in the severe group was not significantly different from that in the mild group of those with non-atopic asthma. The frequency of IL-4+IFN-gamma-IL-10-CD4+ cells (Th2) was significantly higher in the group with mild atopic asthma than in that with mild non-atopic asthma. IFN-gamma+IL-4-IL-10-CD4+ cells (Th1) did not differ between groups, irrespective whether the subjects suffered from atopic or non-atopic asthma.

CONCLUSIONS

IL-10+CD4+ cells in PBMCs may be distinct from Th1 or Th2 and likely have the profile of regulatory T cells. The differential association of IL-10+IFN-gamma-IL-4-CD4+ cells with clinical severity between atopic and non-atopic asthma implies that its pathophysiological significance may differ among asthma phenotypes.

Current status of gene delivery and gene therapy in lacrimal gland using viral vectors

Gene delivery is one of the biggest challenges in the field of gene therapy. It involves the efficient transfer of transgenes into somatic cells for therapeutic purposes. A few major drawbacks in gene delivery include inefficient gene transfer and lack of sustained transgene expression. However, the classical method of using viral vectors for gene transfer has circumvented some of these issues. Several kinds of viruses, including retrovirus, adenovirus, adeno-associated virus, and herpes simplex virus, have been manipulated for use in gene transfer and gene therapy applications. The transfer of genetic material into lacrimal epithelial cells and tissues, both in vitro and in vivo, has been critical for the study of tear secretory mechanisms and autoimmunity of the lacrimal gland. These studies will help in the development of therapeutic interventions for autoimmune disorders such as Sjögren's syndrome and dry eye syndromes which are associated with lacrimal dysfunction. These studies are also critical for future endeavors which utilize the lacrimal gland as a reservoir for the production of therapeutic factors which can be released in tears, providing treatment for diseases of the cornea and posterior segment. This review will discuss the developments related to gene delivery and gene therapy in the lacrimal gland using several viral vector systems.

Interaction between human lung fibroblasts and T-lymphocytes prevents activation of CD4+ cells

Background

T lymphocytes are demonstrated to play an important role in several chronic pulmonary inflammatory diseases. In this study we provide evidence that human lung fibroblasts are capable of mutually interacting with T-lymphocytes leading to functionally significant responses by T-cells and fibroblasts.

Methods

Human lung fibroblast were co-cultured with PMA-ionomycin activated T-CD4 lymphocytes for 36 hours. Surface as well as intracellular proteins expression, relevant to fibroblasts and lymphocytes activation, were evaluated by means of flow cytometry and RT-PCR. Proliferative responses of T lymphocytes to concanavalin A were evaluated by the MTT assay.

Results

In lung fibroblasts, activated lymphocytes promote an increase of expression of cyclooxygenase-2 and ICAM-1, expressed as mean fluorescence intensity (MFI), from 5.4 ± 0.9 and 0.7 ± 0.15 to 9.1 ± 1.5 and 38.6 ± 7.8, respectively. Fibroblasts, in turn, induce a significant reduction of transcription and protein expression of CD69, LFA-1 and CD28 in activated lymphocytes and CD3 in resting lymphocytes. In activated T lymphocytes, LFA-1, CD28 and CD69 expression was 16.6 ± 0.7, 18.9 ± 1.9 and 6.6 ± 1.3, respectively, and was significantly reduced by fibroblasts to 9.4 ± 0.7, 9.4 ± 1.4 and 3.5 ± 1.0. CD3 expression in resting lymphocytes was 11.9 ± 1.4 and was significantly reduced by fibroblasts to 6.4 ± 1.1. Intracellular cytokines, TNF-alpha and IL-10, were evaluated in T lymphocytes. Co-incubation with fibroblasts reduced the number of TNF-alpha positive lymphocytes from 54,4% ± 6.12 to 30.8 ± 2.8, while IL-10 positive cells were unaffected. Finally, co-culture with fibroblasts significantly reduced Con A proliferative response of T lymphocytes, measured as MTT absorbance, from 0.24 ± 0.02 nm to 0.16 ± 0.02 nm. Interestingly, while the activation of fibroblasts is mediated by a soluble factor, a cognate interaction ICAM-1 mediated was demonstrated to be responsible for the modulation of LFA-1, CD28 and CD69.

Conclusion

Findings from this study suggest that fibroblasts play a role in the local regulation of the immune response, being able to modulate effector functions of cells recruited into sites of inflammation.

Different roles of interleukin-10 in onset and resolution of asthmatic responses in allergen-challenged mice

OBJECTIVE

Although interleukin (IL)-10 is an immunoregulatory cytokine produced by various cells including T cells, its precise role in asthma remains uncertain. The aim of this study was to investigate the role of IL-10 in experimental asthma using ovalbumin (OVA)-sensitized mice.

METHODOLOGY

Mice were challenged with OVA aerosol, and airway responsiveness and inflammation were measured. OVA-specific IL-10-producing CD4+ T cells were counted from lung cells collected by enzymatic digestion and stimulated ex vivo with OVA. The effects of an anti-IL-10 antibody on airway responsiveness and inflammation were also evaluated.

RESULTS

The OVA challenge caused airway hyperresponsiveness and eosinophilic inflammation. A significant increase in IL-10-producing CD4+ T cells was observed, mainly in the CD45RB(low) subset, for several days after the OVA challenge. Anti-IL-10 antibody treatment before the OVA challenge did not affect eosinophilic inflammation but significantly inhibited airway hyperresponsiveness 24 h after the OVA challenge. However, anti-IL-10 antibody treatment just before the last OVA challenge significantly attenuated the resolution of eosinophilic inflammation without affecting airway responsiveness 2 weeks after the OVA challenge.

CONCLUSIONS

Intrinsic IL-10 may have a distinct role in the early and late phases of asthmatic responses. In the early phase, IL-10 induces airway hyperresponsiveness, while in the late phase IL-10 contributes to the resolution of eosinophilic inflammation.

The anti-inflammatory effect of exercise

Regular exercise offers protection against all-cause mortality, primarily by protection against cardiovascular disease and Type 2 diabetes mellitus. The latter disorders have been associated with chronic low-grade systemic inflammation reflected by a two- to threefold elevated level of several cytokines. Adipose tissue contributes to the production of TNF-α, which is reflected by elevated levels of soluble TNF-α receptors, IL-6, IL-1 receptor antagonist, and C-reactive protein. We suggest that TNF-α rather than IL-6 is the driver behind insulin resistance and dyslipidemia and that IL-6 is a marker of the metabolic syndrome, rather than a cause. During exercise, IL-6 is produced by muscle fibers via a TNF-independent pathway. IL-6 stimulates the appearance in the circulation of other anti-inflammatory cytokines such as IL-1ra and IL-10 and inhibits the production of the proinflammatory cytokine TNF-α. In addition, IL-6 enhances lipid turnover, stimulating lipolysis as well as fat oxidation. We suggest that regular exercise induces suppression of TNF-α and thereby offers protection against TNF-α-induced insulin resistance. Recently, IL-6 was introduced as the first myokine, defined as a cytokine that is produced and released by contracting skeletal muscle fibers, exerting its effects in other organs of the body. Here we suggest that myokines may be involved in mediating the health-beneficial effects of exercise and that these in particular are involved in the protection against chronic diseases associated with low-grade inflammation such as diabetes and cardiovascular diseases.

Ceftriaxone pharmacokinetics in interleukin-10-treated murine pneumococcal pneumonia

OBJECTIVES

Anti-inflammatory therapy with interleukin-10 (IL-10) was previously reported to reduce pulmonary inflammation and to prevent septicaemia in murine pneumococcal pneumonia treated with ceftriaxone. In the present report, we investigated the influence of pulmonary infection and IL-10 administration on the pharmacokinetics of ceftriaxone.

METHODS

CD1 mice were infected with 10(7) cfu of Streptococcus pneumoniae. Treatments (intraperitoneal) with IL-10 (1 microg per mouse), ceftriaxone (20 mg/kg) or the combination of IL-10 + ceftriaxone were initiated 18 h after infection. Groups of mice were sacrificed at several time points from 5 min to 24 h after initiation of therapy. Ceftriaxone was quantified in blood and lungs using a microbiological assay. Additional groups of mice received a second dose of IL-10 at 36 h post-infection. Survival rates were recorded over 14 days.

RESULTS

The clearance of ceftriaxone was significantly reduced in infected mice compared with that in non-infected animals (P < 0.01), whereas AUC, mean residence time, t(1/2) and AUC(lung)/AUC(serum) were significantly enhanced (P < 0.01, 0.01, 0.05, 0.05). Co-administration of IL-10 with ceftriaxone in infected animals further retained ceftriaxone in the bloodstream and reduced its volume of distribution at steady state and the ratio of AUC(lung)/AUC(serum). IL-10 alone did not modify significantly the pharmacokinetics of ceftriaxone in blood and lungs of non-infected animals.

CONCLUSIONS

The results suggest that pulmonary infection, and therapy with IL-10, both affect the pharmacokinetics of ceftriaxone. Indeed, administration of IL-10 + ceftriaxone improved the survival rate of mice (P < 0.001 compared with therapy with ceftriaxone alone). IL-10 should be considered as an adjunctive therapy to antibiotics against severe infections.

Decrease of interleukin-10-producing T cells in the peripheral blood of severe unstable atopic asthmatics

BACKGROUND

Although IL-10 is known as an immunoregulatory cytokine produced by various cells including T cells, its basic profile in atopic asthma remains uncertain.

OBJECTIVE

The profiles of IL-10 production in circulating CD4+ T cells of atopic asthmatics were investigated with respect to clinical severity.

METHODS

Forty atopic asthmatics were divided into three groups: mild, and severe but stable and severe unstable asthmatics. Eosinophils were counted in the peripheral blood and sputum, and exhaled nitric oxide was assessed. PBMCs were stimulated with or without anti-CD3 and anti-CD28 antibodies and then processed for detecting IL-10-producing CD4+ cells using flow cytometry.

RESULTS

There was no difference in the eosinophil count in blood or sputum and in nitric oxide level among the three groups. IL-10-producing CD4+ cells were mainly detected in a CD45RO+ memory population. The frequency of IL-10-producing cells after stimulation was significantly lower in the severe unstable group compared to the mild group. In addition, the frequency of IL-10-producing cells in the severe unstable group was significantly lower than that in the severe stable group despite the fact that both groups received similar treatments with high-dose inhaled corticosteroids. The IL-10 production of CD4+CD45RO+ cells in response to dexamethasone did not differ among the three groups.

CONCLUSIONS

IL-10-producing CD4+CD45RO+ cells in the peripheral blood are decreased in severe unstable asthmatics, which is not explained by the effect of high-dose inhaled corticosteroid medication.

The role of interleukin 10 in the pathogenesis and potential treatment of skin diseases

Interleukin 10 (IL-10) is a key cytokine produced by a multitude of immune effector cells and possesses distinct regulatory effects on immune functioning in the skin. In this article we report the current understanding of the immunobiology of IL-10 and identify the role of IL-10 in cutaneous infection as well as in autoimmune and neoplastic processes. We reviewed the literature to examine the function of IL-10 in different cutaneous disorders. IL-10 can influence and potentially treat T1/T2 differentiation, antigen-presenting cell functioning, antigen-presenting cell-mediated T-cell activation, and T-cell, B-cell, and mast cell growth and differentiation that is aberrant in various disease processes. The literature consensus is that the multitude of effects of IL-10 contribute to the pathogenesis of different skin disorders. In certain circumstances IL-10 could represent novel therapeutic approaches to treating cutaneous diseases.

LEARNING OBJECTIVE

At the conclusion of this learning activity, participants should be acquainted with the role of IL-10 in many infectious diseases, autoimmune skin disease, inflammatory processes, and malignancy. Its possible role in the resolution of various skin diseases should be better understood.

New therapies for chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is the most common lung disease, carrying a significant mortality and morbidity. None of the therapeutic interventions currently available alter the progression of the disease. As our understanding of the basic mechanisms of alveolar destruction and airflow limitation improves, new targets are identified that may eventually result in treatment options which will affect the progression of this disease. In this review, we discuss some of the novel therapeutic options recently developed that may have an impact on the management of COPD. Future directions in research and development of pharmacological agents based on improved understanding of COPD are also discussed.