The heterogenic properties of monocytes/macrophages and neutrophils in inflammatory response in diabetes

Macrophages in cardiovascular diseases: molecular mechanisms and therapeutic targets

The immune response holds a pivotal role in cardiovascular disease development. As multifunctional cells of the innate immune system, macrophages play an essential role in initial inflammatory response that occurs following cardiovascular injury, thereby inducing subsequent damage while also facilitating recovery. Meanwhile, the diverse phenotypes and phenotypic alterations of macrophages strongly associate with distinct types and severity of cardiovascular diseases, including coronary heart disease, valvular disease, myocarditis, cardiomyopathy, heart failure, atherosclerosis and aneurysm, which underscores the importance of investigating macrophage regulatory mechanisms within the context of specific diseases. Besides, recent strides in single-cell sequencing technologies have revealed macrophage heterogeneity, cell-cell interactions, and downstream mechanisms of therapeutic targets at a higher resolution, which brings new perspectives into macrophage-mediated mechanisms and potential therapeutic targets in cardiovascular diseases. Remarkably, myocardial fibrosis, a prevalent characteristic in most cardiac diseases, remains a formidable clinical challenge, necessitating a profound investigation into the impact of macrophages on myocardial fibrosis within the context of cardiac diseases. In this review, we systematically summarize the diverse phenotypic and functional plasticity of macrophages in regulatory mechanisms of cardiovascular diseases and unprecedented insights introduced by single-cell sequencing technologies, with a focus on different causes and characteristics of diseases, especially the relationship between inflammation and fibrosis in cardiac diseases (myocardial infarction, pressure overload, myocarditis, dilated cardiomyopathy, diabetic cardiomyopathy and cardiac aging) and the relationship between inflammation and vascular injury in vascular diseases (atherosclerosis and aneurysm). Finally, we also highlight the preclinical/clinical macrophage targeting strategies and translational implications.

Study on Dihydromyricetin Improving Aflatoxin Induced Liver Injury Based on Network Pharmacology and Molecular Docking

Aflatoxin B1 (AFB1) is a toxic food/feed contaminant and the liver is its main target organ, thus it poses a great danger to organisms. Dihydromyricetin (DHM), a natural flavonoid compound, can be used as a food additive with high safety and has been shown to have strong hepatoprotective effects. In this experiment, PPI network and KEGG pathway analysis were constructed by network pharmacological analysis technique using software and platforms such as Swiss, String, and David and Cytoscape. We screened AFB1 and DHM cross-targets and pathways of action, followed by molecular docking based on the strength of binding affinity of genes to DHM. In addition, we exposed AFB1 (200 μg/kg) to mice to establish a liver injury model. Histological observation, biochemical assay, oxidative stress indicator assay, TUNEL staining and Western blot were used to evaluate the liver injury. Network pharmacological results were screened to obtain 25 cross-targets of action and 20 pathways of action. It was found that DHM may exert anti-hepatic injury effects by inhibiting the overexpression of Caspase-3 protein and increasing the expression of Bcl-2 protein. DHM (200 mg/kg) was found to reduce AFB1-induced liver indices such as alanine aminotransferase (ALT) and aspartate acyltransferase (AST), and attenuate hepatic histopathological damage through animal models. Importantly, DHM inhibited malondialdehyde (MDA) formation in liver tissue and attenuated AFB1-induced oxidative stress injury by increasing glutathione-S-transferase (GST) glutathione (GPX) catalase (CAT) and superoxide dismutase (SOD). Meanwhile, DHM also restored the expression of anti-apoptotic protein Bcl-2 and antioxidant proteins, Nrf2, Keap1 and its downstream HO-1, and down-regulated the expression of pro-apoptotic proteins Bax and Caspase-3 in AFB1-induced liver tissues. The results confirmed that liver injury caused by AFB1 exposure could be alleviated by DHM, providing valuable guidance for in-depth study of DHM in the treatment of liver-related diseases, and laying the foundation for in-depth development and utilization of DHM.

Adipocyte- and Monocyte-Mediated Vicious Circle of Inflammation and Obesity (Review of Cellular and Molecular Mechanisms)

Monocytes play a key role in the development of metabolic syndrome, and especially obesity. Given the complex features of their development from progenitor cells, whose regulation is mediated by their interactions with bone marrow adipocytes, the importance of a detailed study of the heterogeneous composition of monocytes at the molecular and systemic levels becomes clear. Research argues for monocytes as indicators of changes in the body's metabolism and the possibility of developing therapeutic strategies to combat obesity and components of metabolic syndrome based on manipulations of the monocyte compound of the immune response. An in-depth study of the heterogeneity of bone-marrow-derived monocytes and adipocytes could provide answers to many questions about the pathogenesis of obesity and reveal their therapeutic potential.

Macrophage-based therapy for intervertebral disc herniation: preclinical proof-of-concept

Intervertebral disc (IVD) degeneration and herniation is a leading cause of disability globally and a large unmet clinical need. No efficient non-surgical therapy is available, and there is an urgency for minimally invasive therapies capable of restoring tissue function. IVD spontaneous hernia regression following conservative treatment is a clinically relevant phenomenon that has been linked to an inflammatory response. This study establishes the central role of macrophages in IVD spontaneous hernia regression and provides the first preclinical demonstration of a macrophage-based therapy for IVD herniation. A rat model of IVD herniation was used to test complementary experimental setups: (1) macrophage systemic depletion via intravenous administration of clodronate liposomes (Group CLP2w: depletion between 0 and 2 weeks post-lesion; Group CLP6w: depletion between 2 and 6 weeks post-lesion), and (2) administration of bone marrow-derived macrophages into the herniated IVD, 2 weeks post-lesion (Group Mac6w). Herniated animals without treatment were used as controls. The herniated area was quantified by histology in consecutive proteoglycan/collagen IVD sections at 2 and 6 weeks post-lesion. Clodronate-mediated macrophage systemic depletion was confirmed by flow cytometry and resulted in increased hernia sizes. Bone marrow-derived macrophages were successfully administered into rat IVD hernias resulting in a 44% decrease in hernia size. No relevant systemic immune reaction was identified by flow cytometry, cytokine, or proteomic analysis. Furthermore, a possible mechanism for macrophage-induced hernia regression and tissue repair was unveiled through IL4, IL17a, IL18, LIX, and RANTES increase. This study represents the first preclinical proof-of-concept of macrophage-based immunotherapy for IVD herniation.

The association between a novel inflammatory biomarker, systemic inflammatory response index and the risk of diabetic cardiovascular complications

BACKGROUND AND AIM

Systemic inflammatory response index (SIRI) is a novel inflammatory biomarker. The relationship between SIRI and the risk of diabetic cardiovascular complications is still unclear. The purpose of our study was to address the correlation between SIRI and the risk of cardiovascular diseases (CVD) in diabetes mellitus (DM) patients.

METHODS AND RESULTS

A total of 8759 individuals were selected from the National Health and Nutrition Examination Survey (NHANES) (2015-2020) in our study. Comparing with control (n = 6446) and pre-DM (n = 350) individuals, the DM patients (n = 1963) show the higher SIRI level (all P < 0.001) and prevalence of CVD (all P < 0.001). Furthermore, in a fully adjusted model, we observed the increase of tertiles of SIRI was a risk factor for CVD in DM patients (the middle tertile: 1.80, 95% CI: 1.13-3.13; the highest tertile: 1.91, 95% CI: 1.03-3.22; all P < 0.05), while the relationship between hypersensitive CRP (hs-CRP) and the risk of diabetic cardiovascular complications was not observed (all P > 0.05). Furthermore, the SIRI tertiles-CVD association was significant strongly in patients with high body mass index (BMI; >24 kg/m²) than in those with a low BMI (≤24 kg/m², P for interaction = 0.045). Using restricted cubic splines, we observed a dose-response relation between lg SIRI and the risk of CVD in DM patients.

CONCLUSIONS

The elevated SIRI was independently associated with the increased risk of CVD in the DM population with a high BMI (>24 kg/m²), and its clinical value is greater than hs-CRP.

Clinical study of rhGM-CSF for the treatment of pulmonary exogenous acute respiratory distress syndrome by modulating alveolar macrophage subtypes: A randomized controlled trial

BACKGROUND

By modulating the oxygen partial pressure of alveolar epithelial cells, the granulocyte-macrophage colony-stimulating factor (GM-CSF) can stimulate and enhance the innate immune response in the lungs. This study aimed to investigate the therapeutic efficacy of rhGM-CSF in patients suffering from extrapulmonary-induced acute respiratory distress syndrome (ARDS).

METHODS

A randomized, double-blind, placebo-controlled clinical trial was conducted between February 2018 to July 2019, in which 66 sepsis patients with ARDS were recruited. The study randomly allocated the patients into 2 groups: an experimental group (34 cases receiving rhGM-CSF) and a control group (32 cases receiving placebo). The changes in lung function were assessed using the scores of PaO2/FIO2 ratio, acute physiology and chronic health evaluation II, sequential organ failure assessment, and lung injury. Additionally, the study analyzed the levels of inflammatory cells, HLA-DR (%), high mobility group protein B1 (HMGB-1) (ng/mL), tumor necrosis factor-alpha (pg/mL), IL-6 (pg/mL), and GM-CSF (pg/mL) in both blood and bronchoalveolar lavage fluid.

RESULTS

The study results revealed that the experimental group significantly enhanced their pulmonary function compared to the control group. Moreover, the experimental group demonstrated higher levels of inflammatory cells and HLA-DR, whereas levels of HMGB-1 and tumor necrosis factor-alpha were lower in blood (P < .05, respectively). In addition, the experimental group displayed a higher alternatively activated cell ratio and GM-CSF levels in bronchoalveolar lavage fluid (both P < .05); while HMGB-1 levels were significantly reduced (P < .05). However, no notable difference observed in mortality between the 2 groups (P > .05).

CONCLUSIONS

Administering rhGM-CSF to ARDS patients improves lung function and decreases blood inflammation. Nonetheless, while this treatment demonstrates efficacy in reducing these parameters, it does not significantly impact the incidence of ventilator-associated pneumonia or 28-day mortality in ARDS patients.

C1q and Tumor Necrosis Factor Related Protein 9 Protects from Diabetic Cardiomyopathy by Alleviating Cardiac Insulin Resistance and Inflammation

(1) Background: Diabetic cardiomyopathy is a major health problem worldwide. CTRP9, a secreted glycoprotein, is mainly expressed in cardiac endothelial cells and becomes downregulated in mouse models of diabetes mellitus; (2) Methods: In this study, we investigated the impact of CTRP9 on early stages of diabetic cardiomyopathy induced by 12 weeks of high-fat diet; (3) Results: While the lack of CTRP9 in knock-out mice aggravated insulin resistance and triggered diastolic left ventricular dysfunction, AAV9-mediated cardiac CTRP9 overexpression ameliorated cardiomyopathy under these conditions. At this early disease state upon high-fat diet, no fibrosis, no oxidative damage and no lipid deposition were identified in the myocardium of any of the experimental groups. Mechanistically, we found that CTRP9 is required for insulin-dependent signaling, cardiac glucose uptake in vivo and oxidative energy production in cardiomyocytes. Extensive RNA sequencing from myocardial tissue of CTRP9-overexpressing and knock-out as well as respective control mice revealed that CTRP9 acts as an anti-inflammatory mediator in the myocardium. Hence, CTRP9 knock-out exerted more, while CTRP9-overexpressing mice showed less leukocytes accumulation in the heart during high-fat diet; (4) Conclusions: In summary, endothelial-derived CTRP9 plays a prominent paracrine role to protect against diabetic cardiomyopathy and might constitute a therapeutic target.

Neutrophil dynamics and inflammaging in acute ischemic stroke: A transcriptomic review

Stroke is among the leading causes of death and disability worldwide. Restoring blood flow through recanalization is currently the only acute treatment for cerebral ischemia. Unfortunately, many patients that achieve a complete recanalization fail to regain functional independence. Recent studies indicate that activation of peripheral immune cells, particularly neutrophils, may contribute to microcirculatory failure and futile recanalization. Stroke primarily affects the elderly population, and mortality after endovascular therapies is associated with advanced age. Previous analyses of differential gene expression across injury status and age identify ischemic stroke as a complex age-related disease. It also suggests robust interactions between stroke injury, aging, and inflammation on a cellular and molecular level. Understanding such interactions is crucial in developing effective protective treatments. The global stroke burden will continue to increase with a rapidly aging human population. Unfortunately, the mechanisms of age-dependent vulnerability are poorly defined. In this review, we will discuss how neutrophil-specific gene expression patterns may contribute to poor treatment responses in stroke patients. We will also discuss age-related transcriptional changes that may contribute to poor clinical outcomes and greater susceptibility to cerebrovascular diseases.

Inhibition of ROCK ameliorates pulmonary fibrosis by suppressing M2 macrophage polarisation through phosphorylation of STAT3

BACKGROUND

Emerging evidence provides mechanistic insights into the pathogenesis of pulmonary fibrosis (PF), and rare anti-PF therapeutic method has promising effect in its treatment. Rho-associated coiled-coil kinases (ROCK) inhibition significantly ameliorates bleomycin-induced PF and decreases macrophage infiltration, but the mechanism remains unclear. We established bleomycin and radiation-induced PF to identify the activity of WXWH0265, a newly designed unselective ROCK inhibitor in regulating macrophages.

METHODS

Bleomycin-induced PF was induced by intratracheal instillation and radiation-induced PF was induced by bilateral thoracic irradiation. Histopathological techniques (haematoxylin and eosin, Masson's trichrome and immunohistochemistry) and hydroxyproline were used to evaluate PF severity. Western blot, quantitative real-time reverse transcription-polymerase chain reaction and flow cytometry were performed to explore the underlying mechanisms. Bone marrow-derived macrophages (BMDMs) were used to verify their therapeutic effect. Clodronate liposomes were applied to deplete macrophages and to identify the therapeutic effect of WXWH0265.

RESULTS

Therapeutic administration of ROCK inhibitor ameliorates bleomycin-induced PF by inhibiting M2 macrophages polarisation. ROCK inhibitor showed no significant anti-fibrotic effect in macrophages-depleted mice. Treatment with WXWH0265 demonstrated superior protection effect in bleomycin-induced PF compared with positive drugs. In radiation-induced PF, ROCK inhibitor effectively ameliorated PF. Fibroblasts co-cultured with supernatant from various M2 macrophages phenotypes revealed that M2 macrophages stimulated by interleukin-4 promoted extracellular matrix production. Polarisation of M2 macrophages was inhibited by ROCK inhibitor treatment in vitro. The p-signal transducer and activator of transcription 3 (STAT3) in lung tissue and BMDMs was significantly decreased in PF in vivo and vitro after treated with ROCK inhibitors.

CONCLUSION

Inhibiting ROCK could significantly attenuate bleomycin- and radiation-induced PF by regulating the macrophages polarisation via phosphorylation of STAT3. WXWH0265 is a kind of efficient unselective ROCK inhibitor in ameliorating PF. Furthermore, the results provide empirical evidence that ROCK inhibitor, WXWH0265 is a potential drug to prevent the development of PF.

Cytokines, Chemokines, Insulin and Haematological Indices in Type 2 Diabetic Male Sprague Dawley Rats Infected with Trichinella zimbabwensis

Diabetes mellitus is a chronic metabolic disease induced by the inability to control high blood glucose level. Helminth-induced immunomodulation has been reported to prevent or delay the onset of type 2 diabetes mellitus (T2DM), which, in turn, ameliorates insulin sensitivity. Therefore, there is a need to understand the underlying mechanisms utilized by helminths in metabolism and the induction of immuno-inflammatory responses during helminthic infection and T2DM comorbidity. This study aimed at using a laboratory animal model to determine the cytokines, chemokines and haematological indices in diabetic (T2DM) male Sprague Dawley (SD) rats infected with Trichinella zimbabwensis. One hundred and two male SD rats (160–180 g) were randomly selected into three experimental groups (i. T2DM-induced group (D) ii. T. zimbabwensis infected + T2DM group (TzD) and iii. T. zimbabwensis-infected group (Tz)). Rats selected for the D group and TzD group were injected with 40 mg/kg live weight of streptozotocin (STZ) intraperitoneally to induce T2DM, while animals in the Tz and TzD group were infected with T. zimbabwensis. Results showed that adult T. zimbabwensis worm loads and mean T. zimbabwensis larvae per gram (lpg) of rat muscle were significantly higher (p < 0.001) in the Tz group when compared to the TzD group. Blood glucose levels in the D group were significantly higher (p < 0.001) compared to the TzD group. An increase in insulin concentration was observed among the TzD group when compared to the D group. Liver and muscle glycogen decreased in the D when compared to the TzD group. A significant increase (p < 0.05) in red blood cells (RBCs) was observed in the D group when compared to the TzD and Tz groups. An increase in haematocrit, haemoglobin, white blood cells (WBCs), platelet, neutrophils and monocyte were observed in the D group when compared to the TzD group. TNF-α, IFN-γ, IL-4, IL-10 and IL-13 concentrations were elevated in the TzD group when compared to the D and Tz groups, while IL-6 concentration showed a significant reduction in the Tz when compared to the D and the TzD groups. A significant increase in CCL5 in the D and TzD groups was observed in comparison to the Tz group. CXCL10 and CCL11 concentration also showed an increase in the TzD group in comparison to the Tz and the D groups. Overall, our results confirm that T. zimbabwensis, a parasite which produces tissue-dwelling larvae in the host, regulates T2DM driven inflammation to mediate a positive protective effect against T2DM outcomes.

N-Glycosylation and Inflammation; the Not-So-Sweet Relation

Chronic inflammation is the main feature of many long-term inflammatory diseases such as autoimmune diseases, metabolic disorders, and cancer. There is a growing number of studies in which alterations of N-glycosylation have been observed in many pathophysiological conditions, yet studies of the underlying mechanisms that precede N-glycome changes are still sparse. Proinflammatory cytokines have been shown to alter the substrate synthesis pathways as well as the expression of glycosyltransferases required for the biosynthesis of N-glycans. The resulting N-glycosylation changes can further contribute to disease pathogenesis through modulation of various aspects of immune cell processes, including those relevant to pathogen recognition and fine-tuning the inflammatory response. This review summarizes our current knowledge of inflammation-induced N-glycosylation changes, with a particular focus on specific subsets of immune cells of innate and adaptive immunity and how these changes affect their effector functions, cell interactions, and signal transduction.

Cellular interplay between cardiomyocytes and non-myocytes in diabetic cardiomyopathy

Patients with Type 2 diabetes mellitus (T2DM) frequently exhibit a distinctive cardiac phenotype known as diabetic cardiomyopathy. Cardiac complications associated with T2DM include cardiac inflammation, hypertrophy, fibrosis and diastolic dysfunction in the early stages of the disease, which can progress to systolic dysfunction and heart failure. Effective therapeutic options for diabetic cardiomyopathy are limited and often have conflicting results. The lack of effective treatments for diabetic cardiomyopathy is due in part, to our poor understanding of the disease development and progression, as well as a lack of robust and valid preclinical human models that can accurately recapitulate the pathophysiology of the human heart. In addition to cardiomyocytes, the heart contains a heterogeneous population of non-myocytes including fibroblasts, vascular cells, autonomic neurons and immune cells. These cardiac non-myocytes play important roles in cardiac homeostasis and disease, yet the effect of hyperglycaemia and hyperlipidaemia on these cell types are often overlooked in preclinical models of diabetic cardiomyopathy. The advent of human induced pluripotent stem cells provides a new paradigm in which to model diabetic cardiomyopathy as they can be differentiated into all cell types in the human heart. This review will discuss the roles of cardiac non-myocytes and their dynamic intercellular interactions in the pathogenesis of diabetic cardiomyopathy. We will also discuss the use of sodium-glucose cotransporter 2 inhibitors as a therapy for diabetic cardiomyopathy and their known impacts on non-myocytes. These developments will no doubt facilitate the discovery of novel treatment targets for preventing the onset and progression of diabetic cardiomyopathy.

Delineating the complex mechanistic interplay between NF-κβ driven mTOR depedent autophagy and monocyte to macrophage differentiation: A functional perspective

Autophagy is an extremely essential cellular process aimed to clear redundant and damaged materials, namely organelles, protein aggregates, invading pathogens, etc. through the formation of autophagosomes which are ultimately targeted to lysosomal degradation. In this study, we demonstrated that mTOR dependent classical autophagy is ubiquitously triggered in differentiating monocytes. Moreover, autophagy plays a decisive role in sustaining the process of monocyte to macrophage differentiation. We have delved deeper into understanding the underlying mechanistic complexities that trigger autophagy during differentiation. Intrigued by the significant difference between the protein profiles of monocytes and macrophages, we investigated to learn that autophagy directs monocyte differentiation via protein degradation. Further, we delineated the complex cross-talk between autophagy and cell-cycle arrest in differentiating monocytes. This study also inspects the contribution of adhesion on various steps of autophagy and its ultimate impact on monocyte differentiation. Our study reveals new mechanistic insights into the process of autophagy associated with monocyte differentiation and would undoubtedly help to understand the intricacies of the process better for the effective design of therapeutics as autophagy and autophagy-related processes have enormous importance in human patho-physiology.

Dynamic roles of neutrophils in post-stroke neuroinflammation

Clinical trials involving the blockage of peripheral inflammatory leukocyte recruitment into the brain have puzzlingly led to either no significant improvement in stroke outcome, or even worsened outcomes and increased mortality, prompting a re-evaluation of our understanding into the neuroinflammatory processes after stroke. Whilst traditionally understood as simple effectors of the innate immune system, emerging research in vascular disease biology has redefined the neutrophil as a specialized and highly specific cell type with dynamic functional capacity. Indeed, emerging experimental evidence indicates that neutrophils display diverse roles in the acute stages of ischemic stroke with the ability to elicit both pro-inflammatory and anti-inflammatory effects. Currently, there is some uncertainty as to whether neutrophil diversity is beneficial or harmful in stroke as their interactions with the resident cells of the brain, such as microglia and neurons, would potentially elicit heterogeneous outcomes. Current treatments for patients with stroke aim to remove the vascular blockage and to restore blood flow, but there are currently no drug treatments for managing the loss of functional brain tissue nor restoration of microglial and neuronal damage. If these hypothesized wound-healing functions of neutrophils can be validated in a stroke setting, promoting the recruitment of this type of neutrophils into the injured brain tissue may form a promising therapeutic target for the majority of stroke patients currently without treatment. In this review, we will provide an update on recent research that has explored neutrophil heterogeneity in the neuroinflammatory cascade after ischemic stroke.

Magnetic fields as a potential therapy for diabetic wounds based on animal experiments and clinical trials

Diabetes mellitus (DM) is a chronic metabolic disorder with various complications that poses a huge worldwide healthcare burden. Wounds in diabetes, especially diabetic foot ulcers (DFUs), are difficult to manage, often leading to prolonged wound repair and even amputation. Wound management in people with diabetes is an extremely clinical and social concern. Nowadays, physical interventions gain much attention and have been widely developed in the fields of tissue regeneration and wound healing. Magnetic fields (MFs)-based devices are translated into clinical practice for the treatment of bone diseases and neurodegenerative disorder. This review attempts to give insight into the mechanisms and applications of MFs in wound care, especially in improving the healing outcomes of diabetic wounds. First, we discuss the pathological conditions associated with chronic diabetic wounds. Next, the mechanisms involved in MFs' effects on wounds are explored. At last, studies and reports regarding the effects of MFs on diabetic wounds from both animal experiments and clinical trials are reviewed. MFs exhibit great potential in promoting wound healing and have been practised in the management of diabetic wounds. Further studies on the exact mechanism of MFs on diabetic wounds and the development of suitable MF-based devices could lead to their increased applications into clinical practice.

Diabetic cardiomyopathy and inflammation: development of hostile microenvironment resulting in cardiac damage

Diabetes mellitus is emerging as a major risk factor for heart failure. Diabetic cardiomyopathy is defined as a myocardial dysfunction that is not caused by underlying hypertension or coronary artery disease. Studies about clinical features, natural history and outcomes of the disease are few and often conflicting, because a universally accepted operative definition of diabetic cardiomyopathy is still lacking. Hyperglycemia and related metabolic and endocrine disorders are the triggering factors of myocardial damage in diabetic cardiomyopathy through multiple mechanisms. Among these mechanisms, inflammation has a relevant role, similar to other chronic myocardial disease, such as hypertensive or ischemic heart disease. A balance between inflammatory damage and healing processes is fundamental for homeostasis of myocardial tissue, whereas diabetes mellitus produces an imbalance, promoting inflammation and delaying healing. Therefore, diabetes-related chronic inflammatory state can produce a progressive qualitative deterioration of myocardial tissue, which reflects on progressive left ventricular functional impairment, which can be either diastolic, with prevalent myocardial hypertrophy, or systolic, with prevalent myocardial fibrosis. The aim of this narrative review is to summarize the existing evidence about the role of inflammation in diabetic cardiomyopathy onset and development. Ultimately, potential pharmacological strategies targeting inflammatory response will be reviewed and discussed.

Syringaresinol Protects against Type 1 Diabetic Cardiomyopathy by Alleviating Inflammation Responses, Cardiac Fibrosis, and Oxidative Stress

SCOPE

Syringaresinol (SYR) is a phenolic compound, which could be found in various cereals and medicinal plants. It exerts both anti-inflammatory and antioxidant pharmacological properties. However, little is known about the effect of SYR on modulating diabetic cardiomyopathy. The present study aimed to investigate the pharmacodynamic effect of SYR on diabetic cardiomyopathy and the underlying molecular mechanism.

METHODS AND RESULTS

In STZ-induced type 1 diabetic mice, orally administration with SYR in every other day for 8 weeks significantly improves cardiac dysfunction and preventes cardiac hypertrophy and fibrosis. The macrophage infiltration and oxidative stress biomarkers are also suppressed by SYR without affecting hyperglycemia and body weight. In neonatal cardiomyocytes, high glucose-induced cell apoptosis and fibrosis are potently decreased by SYR, and the inflammatory response and oxidant stress are also alleviated by SYR incubation. Mechanistically, SYR may exert protective effects by restoring suppression of antioxidant kelch-like ECH-associated protein 1 (Keap1)/nuclear factor-E2-related factor 2 (Nrf2) system and abnormal activation of transforming growth factor-β (TGF-β)/mothers against decapentaplegic homolog (Smad) signaling pathway in vitro and in vivo.

CONCLUSION

The results indicated that SYR could be a potential therapeutic agent for the treatment of diabetic cardiomyopathy by inhibiting inflammation, fibrosis, and oxidative stress. The signaling pathway of Keap1/Nrf2 and TGF-β/Smad could be used as therapeutic targets for diabetic complications.

MAP Kinase driven actomyosin rearrangement is a crucial regulator of monocyte to macrophage differentiation

Rearrangement of actin cytoskeleton correlates significantly with the immune responses as the perturbation of cytoskeletal dynamics leads to many immune deficiencies. Mechanistic insights into this correlation remain unknown. Cellular spreading, the most characteristic phenotype associated with monocyte to macrophage differentiation, led us to investigate the contribution of actomyosin dynamics in monocyte differentiation. Our observation revealed that actomyosin reorganization intrinsically governs the process of monocyte to macrophage differentiation. Further, we established that the MAPK-driven signaling pathways regulate the cellular actomyosin dynamics that direct monocyte to macrophage differentiation. We also identified P42/44 Mitogen-Activated Protein Kinase (P42/44 MAPK), P38 Mitogen-Activated Protein Kinase (P38 MAPK), MAP Kinase Activated Protein Kinase 2 (MK-2), Heat Shock Protein 27 (Hsp-27), Lim Kinase (Lim K), non-muscle cofilin (n-cofilin), Myosin Light Chain Kinase (MLCK) and Myosin Light Chain (MLC) as critical components of the signaling network. Moreover, we have shown the involvement of the same signaling cascade in 3D gel-like microenvironment induced spontaneous monocyte to macrophage differentiation and in human blood-derived PBMC differentiation. Our study reveals new mechanistic insights into the process of monocyte to macrophage differentiation.

Neutrophils activated by BJcuL, a C-type lectin isolated from Bothrops jararacussu venom, decrease the invasion potential of neuroblastoma SK-N-SH cells in vitro

BACKGROUND

Neuroblastoma is a pediatric tumor with a mortality rate of 40% in the most aggressive cases. Tumor microenvironment components as immune cells contribute to the tumor progression; thereby, the modulation of immune cells to a pro-inflammatory and antitumoral profile could potentialize the immunotherapy, a suggested approach for high-risk patients. Preview studies showed the antitumoral potential of BJcuL, a C- type lectin isolated from Bothrops jararacussu venom. It was able to induce immunomodulatory responses, promoting the rolling and adhesion of leukocytes and the activation of neutrophils.

METHODS

SK-N-SH cells were incubated with conditioned media (CM) obtained during the treatment of neutrophils with BJcuL and fMLP, a bacteria-derived peptide highly effective for activating neutrophil functions. Then we evaluated the effect of the same stimulation on the co-cultivation of neutrophils and SK-N-SH cells. Tumor cells were tested for viability, migration, and invasion potential.

RESULTS

In the viability assay, only neutrophils treated with BJcuL (24 h) and cultivated with SK-N-SH were cytotoxic. Migration of tumor cells decreased when incubated directly (p < 0.001) or indirectly (p < 0.005) with untreated neutrophils. When invasion potential was evaluated, neutrophils incubated with BJcuL reduced the total number of colonies of SK-N-SH cells following co-cultivation for 24 h (p < 0.005). Treatment with CM resulted in decreased anchorage-free survival following 24 h of treatment (p < 0.001).

CONCLUSION

Data demonstrated that SK-N-SH cells maintain their migratory potential in the face of neutrophil modulation by BJcuL, but their invasive capacity was significantly reduced.

Collagen Peptides Isolated from Salmo salar and Tilapia nilotica Skin Accelerate Wound Healing by Altering Cutaneous Microbiome Colonization via Upregulated NOD2 and BD14

Collagen peptides can promote wound healing and are closely related to microbiome colonization. We investigated the relationship among collagen peptides, wound healing, and wound microflora colonization by administering the murine wound model with Salmo salar skin collagen peptides (Ss-SCPs) and Tilapia nilotica skin collagen peptides (Tn-SCPs). We analyzed the vascular endothelial growth factor (VEGF), fibroblast growth factors (β-FGF), pattern recognition receptor (NOD2), antimicrobial peptides (β-defence14, BD14), proinflammatory (TNF-α, IL-6, and IL-8) and anti-inflammatory (IL-10) cytokines, macrophages, neutrophil infiltration levels, and microbial communities in the rat wound. The healing rates of the Ss-SCP- and Tn-SCP-treated groups were significantly accelerated, associated with decreased TNF-α, IL-6, and IL-8 and upregulated BD14, NOD2, IL-10, VEGF, and β-FGF. Accelerated healing in the collagen peptide group shows that the wound microflora such as Leuconostoc, Enterococcus, and Bacillus have a positive effect on wound healing (P < 0.01). Other microbiome species such as Stenotrophomonas, Bradyrhizobium, Sphingomonas, and Phyllobacterium had a negative influence and decreased colonization (P < 0.01). Altogether, these studies show that collagen peptide could upregulate wound NOD2 and BD14, which were implicated in microflora colonization regulation in the wound tissue and promoted wound healing by controlling the inflammatory reaction and increasing wound angiogenesis and collagen deposition.

Cardiomyopathy Associated with Diabetes: The Central Role of the Cardiomyocyte

The term diabetic cardiomyopathy (DCM) labels an abnormal cardiac structure and performance due to intrinsic heart muscle malfunction, independently of other vascular co-morbidity. DCM, accounting for 50%–80% of deaths in diabetic patients, represents a worldwide problem for human health and related economics. Optimal glycemic control is not sufficient to prevent DCM, which derives from heart remodeling and geometrical changes, with both consequences of critical events initially occurring at the cardiomyocyte level. Cardiac cells, under hyperglycemia, very early undergo metabolic abnormalities and contribute to T helper (Th)-driven inflammatory perturbation, behaving as immunoactive units capable of releasing critical biomediators, such as cytokines and chemokines. This paper aims to focus onto the role of cardiomyocytes, no longer considered as “passive” targets but as “active” units participating in the inflammatory dialogue between local and systemic counterparts underlying DCM development and maintenance. Some of the main biomolecular/metabolic/inflammatory processes triggered within cardiac cells by high glucose are overviewed; particular attention is addressed to early inflammatory cytokines and chemokines, representing potential therapeutic targets for a prompt early intervention when no signs or symptoms of DCM are manifesting yet. DCM clinical management still represents a challenge and further translational investigations, including studies at female/male cell level, are warranted.

The adaptive immune role of metallothioneins in the pathogenesis of diabetic cardiomyopathy: good or bad

Diabetes is a metabolic disorder characterized by hyperglycemia, resulting in low-grade systemic inflammation. Diabetic cardiomyopathy (DCM) is a common complication among diabetic patients, and the mechanism underlying its induction of cardiac remodeling and dysfunction remains unclear. Numerous experimental and clinical studies have suggested that adaptive immunity, especially T lymphocyte-mediated immunity, plays a potentially important role in the pathogenesis of diabetes and DCM. Metallothioneins (MTs), cysteine-rich, metal-binding proteins, have antioxidant properties. Some potential mechanisms underlying the cardioprotective effects of MTs include the role of MTs in calcium regulation, zinc homeostasis, insulin sensitization, and antioxidant activity. Moreover, metal homeostasis, especially MT-regulated zinc homeostasis, is essential for immune function. This review discusses aberrant immune regulation in diabetic heart disease with respect to endothelial insulin resistance and the effects of hyperglycemia and hyperlipidemia on tissues and the different effects of intracellular and extracellular MTs on adaptive immunity. This review shows that intracellular MTs are involved in naïve T-cell activation and reduce regulatory T-cell (Treg) polarization, whereas extracellular MTs promote proliferation and survival in naïve T cells and Treg polarization but inhibit their activation, thus revealing potential therapeutic strategies targeting the regulation of immune cell function by MTs.

Heterogeneous macrophages: Supersensors of exogenous inducing factors

As heterogeneous immune cells, macrophages mount effective responses to various internal and external changes during disease progression. Macrophage polarization, rather than macrophage heterogenization, is often used to describe the functional differences between macrophages. While macrophage polarization partially contributes to heterogeneity, it does not completely explain the concept of macrophage heterogeneity. At the same time, there are abundant and sophisticated endogenous and exogenous substances that can affect macrophage heterogeneity. While the research on endogenous factors has been systematically reviewed, the findings on exogenous factors have not been well summarized. Hence, we reviewed the characteristics and inducing factors of heterogeneous macrophages to reveal their functional plasticity as well as their targeting manoeuvreability. In the process of constructing and analysing a network organized by disease-related cells and molecules, paying more attention to heterogeneous macrophages as mediators of this network may help to explore a novel entry point for early prevention of and intervention in disease.

Prior β-blocker treatment decreases leukocyte responsiveness to injury

Following injury, leukocytes are released from hematopoietic organs and migrate to the site of damage to regulate tissue inflammation and repair, however leukocytes lacking β2-adrenergic receptor (β2AR) expression have marked impairments in these processes. β-blockade is a common strategy for the treatment of many cardiovascular etiologies, therefore the objective of our study was to assess the impact of prior β-blocker treatment on baseline leukocyte parameters and their responsiveness to acute injury. In a temporal and βAR isoform-dependent manner, chronic β-blocker infusion increased splenic vascular cell adhesion molecule-1 (VCAM-1) expression and leukocyte accumulation (monocytes/macrophages, mast cells and neutrophils) and decreased chemokine receptor 2 (CCR2) expression, migration of bone marrow cells (BMC) and peripheral blood leukocytes (PBL), as well as infiltration into the heart following acute cardiac injury. Further, CCR2 expression and migratory responsiveness was significantly reduced in the PBL of patients receiving β-blocker therapy compared to β-blocker-naïve patients. These results highlight the ability of chronic β-blocker treatment to alter baseline leukocyte characteristics that decrease their responsiveness to acute injury and suggest that prior β-blockade may act to reduce the severity of innate immune responses.

Theoretical Studies on the Engagement of Interleukin 18 in the Immuno-Inflammatory Processes Underlying Atherosclerosis

Interleukin 18 (IL-18) is one of the pro-inflammatory cytokines expressed by macrophages, suggesting that it plays important physiological and immunological functions, among the others: stimulation of natural killers (NKs) and T cells to interferon gamma (IFN- γ ) synthesis. IL-18 was originally identified as interferon gamma inducing factor and now it is recognized as multifunctional cytokine, which has a role in regulation of innate and adaptive immune responses. Therefore, in order to investigate IL-18 contribution to the immuno-inflammatory processes underlying atherosclerosis, a systems approach has been used in our studies. For this purpose, a model of the studied phenomenon, including selected pathways, based on the Petri-net theory, has been created and then analyzed. Two pathways of IL-18 synthesis have been distinguished: caspase 1-dependent pathway and caspase 1-independent pathway. The analysis based on t-invariants allowed for determining interesting dependencies between IL-18 and different types of macrophages: M1 are involved in positive regulation of IL-18, while M2 are involved in negative regulation of IL-18. Moreover, the obtained results showed that IL-18 is produced more often via caspase 1-independent pathway than caspase 1-dependent pathway. Furthermore, we found that this last pathway may be associated with caspase 8 action.

The Role of Leukocytes in Diabetic Cardiomyopathy

Diabetes is predominant risk factor for cardiovascular diseases such as myocardial infarction and heart failure. Recently, leukocytes, particularly neutrophils, macrophages, and lymphocytes, have become targets of investigation for their potential role in a number of chronic inflammatory diseases such as diabetes and heart failure. While leukocytes contribute significantly to the progression of diabetes and heart failure individually, understanding their participation in the pathogenesis of diabetic heart failure is much less understood. The present review summarizes the role of leukocytes in the complex interplay between diabetes and heart failure, which is critical to the discovery of new targeted therapies for diabetic cardiomyopathy.

Partners in crime: neutrophils and monocytes/macrophages in inflammation and disease

Neutrophils are becoming recognized as highly versatile and sophisticated cells that display de novo synthetic capacity and potentially prolonged lifespan. Emerging concepts such as neutrophil heterogeneity and plasticity have revealed that, under pathological conditions, neutrophils may differentiate into discrete subsets defined by distinct phenotypic and functional characteristics. Indeed, these newly described neutrophil subsets will undoubtedly add to the already complex interactions between neutrophils and other immune cell types for an effective immune response. The interactions between neutrophils and monocytes/macrophages enable the host to efficiently defend against and eliminate foreign pathogens. However, it is also becoming increasingly clear that these interactions can be detrimental to the host if not tightly regulated. In this review, we will explore the functional cooperation of neutrophil and monocytes/macrophages in homeostasis, during acute inflammation and in various disease settings. We will discuss this in the context of cardiovascular disease in the form of atherosclerosis, an autoimmune disease mainly occurring in the kidneys, as well as the unique intestinal immune response of the gut that does not conform to the norms of the typical immune system.

Exendin-4, a glucagon-like peptide-1 analogue accelerates healing of chronic gastric ulcer in diabetic rats

Background

Diabetes mellitus is an independent risk factor for impaired healing of peptic ulcers, and there are currently no supplementary therapeutics other than the standard antipeptic medicine to improve the ulcer healing in diabetes. This study examined the potential pleiotropic effect of a glucagon-like peptide (Glp)-1 analogue exendin (Ex)-4 on the regeneration of gastric ulcer in streptozotocin-induced diabetic rats.

Methods and results

Chronic ulcer was created in rat stomach by submucosal injection of acetic acid and peri-ulcer tissues were analyzed 7 days after operation. Ulcer wound healing was impaired in diabetic rats with suppressed tissue expression of eNOS and enhanced levels of pro-inflammatory reactions. Treatment with intraperitoneal injection of Ex4 (0.5 μg/kg/d) significantly reduced the area of gastric ulcer without changing blood glucose level. Ex-4 restored the expression of pro-angiogenic factors, and attenuated the generation of regional inflammation and superoxide anions. The improvement of ulcer healing was associated with increased expression of MMP-2 and formation of granulation tissue in the peri-ulcer area.

Conclusion

Administration of Ex4 may induce pro-angiogenic, anti-inflammatory and anti-oxidative reactions in the peri-ulcer tissue of diabetic rats that eventually enhances tissue granulation and closure of ulcerative wounds. Our results support the potential clinical application of Glp-1 analogues as supplementary hypoglycemic agents in the antipeptic ulcer medication in diabetes.

Oral delivery of staphylococcal nuclease by Lactococcus lactis prevents type 1 diabetes mellitus in NOD mice

Type 1 diabetes mellitus (T1DM) is an autoimmune disease characterized by the self-destruction of insulin-producing β cells. Recently, studies have revealed that neutrophils contribute to the early pathological injury to the pancreas, predominantly via the formation of neutrophil extracellular traps (NETs). To determine whether early intervention targeting NETs with staphylococcal nuclease (SNase) can delay the onset of T1DM, non-obese diabetic (NOD) mice were orally administered recombinant Lactococcus lactis (L. lactis) expressing SNase. The results showed that NETs were effectively disrupted by SNase both in vivo and in vitro, leading to a significant decrease in neutrophil-derived circulating free DNA (cf-DNA/NETs), neutrophil elastase (NE), and protease 3 (PR3) in the serum compared with the controls. In addition, SNase effectively regulated the blood glucose levels of NOD mice, and the onset of diabetes was postponed with reduced mortality and morbidity. Recombinant L. lactis also ameliorated inflammation in NOD mice, as evidenced by the remarkable increase in IL-4 and reductions in TNF-α and CRP. Moreover, HE staining results showed that L. lactis expressing SNase exerted protective effects on pancreatic islets and relieved inflammation of the small intestine in NOD mice. Hence, the present study indicates that the oral delivery of SNase by L. lactis can effectively prevent T1DM, ameliorate inflammation, and contribute to immunomodulatory balance in NOD mice.

Altered levels of circulating cytokines and microRNAs in lean and obese individuals with prediabetes and type 2 diabetes

Today obesity and type 2 diabetes (T2D) have both reached epidemic proportions. However, our current understanding of the primary mechanisms leading to these diseases is still limited due to the complex multifactorial nature of the underlying phenomena. We hypothesize that the levels of specific cytokines and miRNAs vary across the diabetes spectrum and unique signatures associated with them may serve as early biomarkers of the disease and provide insights into respective pathogenetic mechanisms. In this study, we measured the circulating levels of cytokines and microRNAs (miRNAs) in lean and obese humans with prediabetes (n = 21), T2D (n = 17), and healthy controls (n = 20) (ORIGINS trial, NCT02226640). Data were analyzed by fitting linear models adjusted for confounding variables (BMI, age, and gender in the diabetes context and age, gender, and diabetes status in the obesity context) and implementing nonparametric randomization-based tests for statistical inference. Group differences and correlations (r > 0.3) between variables with P < 0.05 were considered significant. False discovery rates (FDR) correcting for multiple testing were calculated using the Benjamini-Hochberg correction. We found a number of circulating cytokines and miRNAs deregulated in subjects with obesity, prediabetes, and T2D. Specifically, cytokines IL-6, IL-8, IL-10, IL-12, and SFRP4, as well as miRNAs miR-21, miR-24.1, miR-27a, miR-28-3p, miR-29b, miR-30d, miR-34a, miR-93, miR-126, miR-146a, miR-148, miR-150, miR-155, and miR-223, significantly changed across the diabetes spectrum, and were associated with measures of pancreatic islet β cell function and glycemic control, among others. Notably, SFRP4 was the only studied cytokine that was significantly associated with obesity, prediabetes, and T2D, which underscores the important role of this molecule during disease development and progression. Our data suggest that changes in circulating miRNAs and cytokines may have clinical utility as biomarkers of prediabetes.

Peripheral blood mononuclear cells from rat model of pleurisy: The effects of hesperidin on ectoenzymes activity, apoptosis, cell cycle and reactive oxygen species production

The present study investigates the effect of hesperidin; a flavonone commonly found in citrus fruits, on the ectoenzymes (ectonucleotidase and ecto-adenosine deaminase) activity, cell viability, apoptosis, cell cycle arrest and reactive oxygen species production in peripheral blood mononuclear cells (PBMCs) from rat model of pleurisy. Wistar rats were pretreated with either saline or hesperidin (80mg/kg) by oral gavage for 21days and injected intrapleurally with 2% carrageenan or saline on the 22nd day. PBMCs were subsequently prepared after 4h of carrageenan induction. The results revealed that hesperidin may exhibit its anti-inflammatory effects through possible modulation of ectonucleotidase (E-NTPDase) and ecto-adenosine deaminase (E-ADA) activities, reduction of intracellular reactive oxygen species, prevention of DNA damage and modulation of apoptosis as well as activation of cell cycle arrest. This study suggests some possible underlying anti-inflammatory mechanisms of hesperidin on PBMCs in acute inflammatory condition. Furthermore, hesperidin may minimize oxidative injury mediated pleurisy in rat.

Immune modulation of some autoimmune diseases: the critical role of macrophages and neutrophils in the innate and adaptive immunity

Macrophages and neutrophils are key components involved in the regulation of numerous chronic inflammatory diseases, infectious disorders, and especially certain autoimmune disease. However, little is known regarding the contribution of these cells to the pathogenesis of autoimmune disorders. Recent studies have aimed to clarify certain important factors affecting the immunogenicity of these cells, including the type and dose of antigen, the microenvironment of the cell-antigen encounter, and the number, subset, and phenotype of these cells, which can prevent or induce autoimmune responses. This review highlights the role of macrophage subsets and neutrophils in injured tissues, supporting their cooperation during the pathogenesis of certain autoimmune diseases.

Control of inflammatory responses by ceramide, sphingosine 1-phosphate and ceramide 1-phosphate

Inflammation is a network of complex processes involving a variety of metabolic and signaling pathways aiming at healing and repairing damage tissue, or fighting infection. However, inflammation can be detrimental when it becomes out of control. Inflammatory mediators involve cytokines, bioactive lipids and lipid-derived metabolites. In particular, the simple sphingolipids ceramides, sphingosine 1-phosphate, and ceramide 1-phosphate have been widely implicated in inflammation. However, although ceramide 1-phosphate was first described as pro-inflammatory, recent studies show that it has anti-inflammatory properties when produced in specific cell types or tissues. The biological functions of ceramides and sphingosine 1-phosphate have been extensively studied. These sphingolipids have opposing effects with ceramides being potent inducers of cell cycle arrest and apoptosis, and sphingosine 1-phosphate promoting cell growth and survival. However, the biological actions of ceramide 1-phosphate have only been partially described. Ceramide 1-phosphate is mitogenic and anti-apoptotic, and more recently, it has been demonstrated to be key regulator of cell migration. Both sphingosine 1-phosphate and ceramide 1-phosphate are also implicated in tumor growth and dissemination. The present review highlights new aspects on the control of inflammation and cell migration by simple sphingolipids, with special emphasis to the role played by ceramide 1-phosphate in controlling these actions.

Neutrophils in the Tumor Microenvironment

Neutrophils are the first responders to sites of acute tissue damage and infection. Recent studies suggest that in addition to neutrophil apoptosis, resolution of neutrophil inflammation at wounds can be mediated by reverse migration from tissues and transmigration back into the vasculature. In settings of chronic inflammation, neutrophils persist in tissues, and this persistence has been associated with cancer progression. However, the role of neutrophils in the tumor microenvironment remains controversial, with evidence for both pro- and anti-tumor roles. Here we review the mechanisms that regulate neutrophil recruitment and resolution at sites of tissue damage, with a specific focus on the tumor microenvironment. We discuss the current understanding as to how neutrophils alter the tumor microenvironment to support or hinder cancer progression, and in this context outline gaps in understanding and important areas of inquiry.

Uncovering novel 3-hydroxy-4-pyridinone metal ion complexes with potential anti-inflammatory properties

Ligands of the 3-hydroxy-4-pyridinone (3,4-HPO) type, with one (Hmpp) or two methyl groups (Hdmpp), have been reported to possess biomedical, chemical and analytical applications. In this first screening study aiming to uncover new promising agents to mitigate the oxidative damage highly present in several metabolic disorders, such as diabetes mellitus, we assessed the potential of twelve 3,4-HPO metal ion complexes to modulate oxidative burst in human neutrophils. Metal ion 3,4-HPO complexes of Ni, Fe, V, Co, Cu and Zn were synthesized and tested up to 15μM. Among all the compounds, [Cu(mpp)2] and [Cu(dmpp)2] exhibited the highest scavenging capacity against superoxide radical (O2(-)) (IC50=0.36±0.07 and 0.30±0.06μM, respectively) and against hypochlorous acid (HOCl) (IC50=0.6±0.3 and 0.4±0.1μM, respectively). In the particular case of O2(-), [Fe(mpp)3] and [Fe(dmpp)3] (both at 15μM) presented 35% and 22% of inhibition, respectively, while all the other compounds were neither able to scavenge O2(-) nor stimulate its production. Regarding the scavenging capacity against hydrogen peroxide (H2O2), all the compounds showed low efficiency (from 6-39%). Finally, with exception of [VO(mpp)2] and [VO(dmpp)2], all compounds exhibited scavenging activity against HOCl (39-81%) and the most efficient compounds were Cu(II) and Zn(II) complexes. Thus, these preliminary results uncover promising new metal ion complexes, inhibitors of neutrophil's oxidative burst, with potential anti-inflammatory properties, which may be seen as an useful strategy for further studies in the treatment of a number of diseases where oxidative damage is a serious issue.

Activation and resolution of periodontal inflammation and its systemic impact

Inflammation is a highly organized event impacting upon organs, tissues and biological systems. Periodontal diseases are characterized by dysregulation or dysfunction of resolution pathways of inflammation that results in failure to heal and in a dominant chronic, progressive, destructive and predominantly unresolved inflammation. The biological consequences of inflammatory processes may be independent of the etiological agents, such as trauma, microbial organisms and stress. The impact of the inflammatory pathological process depends upon the tissues or organ system affected. Whilst mediators are similar, there is tissue specificity for the inflammatory events. It is plausible that inflammatory processes in one organ could directly lead to pathologies in another organ or tissue. Communication between distant parts of the body and their inflammatory status is also mediated by common signaling mechanisms mediated via cells and soluble mediators. This review focuses on periodontal inflammation, its systemic associations and advances in therapeutic approaches based on mediators acting through orchestration of natural pathways to resolution of inflammation. We also discuss a new treatment concept in which natural pathways of resolution of periodontal inflammation can be used to limit systemic inflammation and promote healing and regeneration.

TNF-α-mediated microRNA-136 induces differentiation of myeloid cells by targeting NFIA

Immune cell-lineage specification and function are influenced by progenitor origin and environmental factors. The mechanism of differentiation of immune cells, such as neutrophils, monocytes, and myeloid-derived suppressor cells, in inflammatory environments has not been elucidated completely. In this study, we have identified human microRNA-136 as a positive regulator of the differentiation of granulocytes and monocytes. Ectopic microRNA-136 induced cells to express higher levels of CD11b, CD14, and C/EBPε, secrete more cytokines, and synthesize higher levels of reactive oxygen species and H(2)O(2). microRNA-136 was shown to target and degrade multiple differentiation-associated molecules, such as the transcription factor NFIA, which induced the release of another microRNA, microRNA-223, with the ability to promote CD11b expression. Furthermore, microRNA-136 expression was remarkably increased by TNF-α, which activated NF-κB to bind to the DNA-promoter region controlling microRNA-136 expression. Additionally, TNF-α may alter NFIA expression through its modulation of microRNA-136 expression. Thus, TNF-α-mediated microRNA-136 may play a critical role in the generation and differentiation of inflammatory immune cells.