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Current treatments for diabetic retinopathy (DR) target late stages when vision has already been significantly affected. Accumulating evidence suggests that neuroinflammation plays a major role in the pathogenesis of DR, resulting in the disruption of the blood-retinal barrier. Suppressors of cytokine signaling (SOCS) are cytokine-inducible proteins that function as a negative feedback loop regulating cytokine responses. On this basis, the aim of the present study was to evaluate the effect of a SOCS1-derived peptide administered by eye drops (2 weeks) on retinal neuroinflammation and early microvascular abnormalities in a db/db mouse model. In brief, we found that SOCS1-derived peptide significantly reduced glial activation and neural apoptosis induced by diabetes, as well as retinal levels of proinflammatory cytokines. Moreover, a significant improvement of electroretinogram parameters was observed, thus revealing a clear impact of the histological findings on global retinal function. Finally, SOCS1-derived peptide prevented the disruption of the blood-retinal barrier. Overall, our results suggest that topical administration of SOCS1-derived peptide is effective in preventing retinal neuroinflammation and early microvascular impairment. These findings could open up a new strategy for the treatment of early stages of DR.

Dysregulated lipid metabolism induces an inflammatory and immune response leading to atherosclerosis. Conversely, inflammation may alter lipid metabolism. Recent treatment strategies in secondary prevention of atherosclerosis support beneficial effects of both anti-inflammatory and lipid-lowering therapies beyond current targets. There is a controversy about the possibility that anti-inflammatory effects of lipid-lowering therapy may be either independent or not of a decrease in low-density lipoprotein cholesterol. In this Position Paper, we critically interpret and integrate the results obtained in both experimental and clinical studies on anti-inflammatory actions of lipid-lowering therapy and the mechanisms involved. We highlight that: (i) besides decreasing cholesterol through different mechanisms, most lipid-lowering therapies share anti-inflammatory and immunomodulatory properties, and the anti-inflammatory response to lipid-lowering may be relevant to predict the effect of treatment, (ii) using surrogates for both lipid metabolism and inflammation as biomarkers or vascular inflammation imaging in future studies may contribute to a better understanding of the relative importance of different mechanisms of action, and (iii) comparative studies of further lipid lowering, anti-inflammation and a combination of both are crucial to identify effects that are specific or shared for each treatment strategy.

Introduction: Diabetic nephropathy (DN) is the leading cause of chronic kidney disease (CKD) and end-stage renal disease (ESRD). Beyond the new anti-diabetic drugs that possess markedly cardiovascular and renal protective effects, no novel direct therapies for DN have become available on the market in the last twenty years. Recently well-designed clinical trials for the treatment of DN, with attractive pathogenetic rationale, e.g. bardoxolone and atrasentan, were canceled or stopped because of safety concerns or lack of reaching the end points, respectively., Areas Covered: In this review, we focus on the involvement of inflammation in the pathogenesis of DN. We update information from recent experimental and clinical studies that reported beneficial effects of several agents targeting chemokines, cytokines, transcription factors and kinases as well as several compounds with anti-inflammatory properties on DN., Expert Opinion: Inflammation plays a key role in the DN progression. Preclinical studies have identified several anti-inflammatory molecules that effective decrease albuminuria and/or proteinuria. However, limited clinical trials in humans have been performed to confirm these results. Inhibitors of CCL2/CCR2, IL-1β and JAK/STAT pathways, and Nrf2 inducers are promising therapeutic options to improve the renal outcome of patients with DN, but appropriate clinical trials are necessary.

Branched-chain amino acids (BCAA: leucine, isoleucine and valine) are essential amino acids implicated in glucose metabolism and maintenance of correct brain function. Elevated BCAA levels can promote an inflammatory response in peripheral blood mononuclear cells. However, there are no studies analysing the direct effects of BCAA on endothelial cells (ECs) and its possible modulation of vascular function. In vitro and ex vivo studies were performed in human ECs and aorta from male C57BL/6J mice, respectively. In ECs, BCAA (6 mmol/L) increased eNOS expression, reactive oxygen species production by mitochondria and NADPH oxidases, peroxynitrite formation and nitrotyrosine expression. Moreover, BCAA induced pro-inflammatory responses through the transcription factor NF-κB that resulted in the release of intracellular adhesion molecule-1 and E-selectin conferring endothelial activation and adhesion capacity to inflammatory cells. Pharmacological inhibition of mTORC1 intracellular signalling pathway decreased BCAA-induced pro-oxidant and pro-inflammatory effects in ECs. In isolated murine aorta, BCAA elicited vasoconstrictor responses, particularly in pre-contracted vessels and after NO synthase blockade, and triggered endothelial dysfunction, effects that were inhibited by different antioxidants, further demonstrating the potential of BCAA to induce oxidative stress with functional impact. In summary, we demonstrate that elevated BCAA levels generate inflammation and oxidative stress in ECs, thereby facilitating inflammatory cells adhesion and endothelial dysfunction. This might contribute to the increased cardiovascular risk observed in patients with elevated BCAA blood levels., (© 2018 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.)

Dyslipidaemia and inflammation are closely interconnected in their contribution to atherosclerosis. In fact, low-density lipoprotein (LDL)-lowering drugs have anti-inflammatory effects. The Canakinumab Antiinflammatory Thrombosis Outcome Study (CANTOS) has shown that interleukin (IL)-1β blockade reduces the incidence of cardiovascular events in patients with previous myocardial infarction and C-reactive protein levels >2 mg/L. These data confirm the connection between lipids and inflammation, as lipids activate the Nod-like receptor protein 3 inflammasome that leads to IL-1β activation. LDL-lowering drugs are the foundation of cardiovascular prevention. Now, the CANTOS trial demonstrates that combining them with IL-1β blockade further decreases the incidence of cardiovascular events. However, both therapies are not at the same level, given the large evidence showing that LDL-lowering drugs reduce cardiovascular risk as opposed to only one randomized trial of IL-1β blockade. In addition, IL-1β blockade has only been studied in patients with C-reactive protein >2 mg/L, while the benefit of LDL-lowering is not restricted to these patients. Also, lipid-lowering drugs are not harmful even at very low ranges of LDL, while anti-inflammatory therapies may confer a higher risk of developing fatal infections and sepsis. In the future, more clinical trials are needed to explore whether targeting other inflammatory molecules, both related and unrelated to the IL-1β pathway, reduces the cardiovascular risk. In this regard, the ongoing trials with methotrexate and colchicine may clarify whether the cardiovascular benefit of IL-1β blockade extends to other anti-inflammatory mechanisms. A positive result would represent a major change in the future treatment of atherosclerosis.

Cyclosporine A (CsA) successfully prevents allograft rejection, but nephrotoxicity is still a dose-limiting adverse effect. TLR4 activation promotes kidney damage but whether this innate immunity receptor mediates CsA nephrotoxicity is unknown. The in vivo role of TLR4 during CsA nephrotoxicity was studied in mice co-treated with CsA and the TLR4 inhibitor TAK242 and also in TLR4 -/- mice. CsA-induced renal TLR4 expression in wild-type mice. Pharmacological or genetic targeting of TLR4 reduced the activation of proinflammatory signaling, including JNK/c-jun, JAK2/STAT3, IRE1α and NF-κB and the expression of Fn14. Expression of proinflammatory factors and cytokines was also decreased, and kidney monocyte and lymphocyte influx was prevented. TLR4 inhibition also reduced tubular damage and drastically prevented the development of kidney fibrosis. In vivo and in vitro CsA promoted secretion of the TLR ligand HMGB1 by tubular cells upstream of TLR4 activation, and prevention of HMGB1 secretion significantly reduced CsA-induced synthesis of MCP-1, suggesting that HMGB1 may be one of the mediators of CsA-induced TLR4 activation. These results suggest that TLR4 is a potential pharmacological target in CsA nephrotoxicity.

Leucine, isoleucine and valine are essential aminoacids termed branched-chain amino acids (BCAA) due to its aliphatic side-chain. In several pathological and physiological conditions increased BCAA plasma concentrations have been described. Elevated BCAA levels predict insulin resistance development. Moreover, BCAA levels higher than 2mmol/L are neurotoxic by inducing microglial activation in maple syrup urine disease. However, there are no studies about the direct effects of BCAA in circulating cells. We have explored whether BCAA could promote oxidative stress and pro-inflammatory status in peripheral blood mononuclear cells (PBMCs) obtained from healthy donors. In cultured PBMCs, 10mmol/L BCAA increased the production of reactive oxygen species (ROS) via both NADPH oxidase and the mitochondria, and activated Akt-mTOR signalling. By using several inhibitors and activators of these molecular pathways we have described that mTOR activation by BCAA is linked to ROS production and mitochondrial dysfunction. BCAA stimulated the activation of the redox-sensitive transcription factor NF-κB, which resulted in the release of pro-inflammatory molecules, such as interleukin-6, tumor necrosis factor-α, intracellular adhesion molecule-1 or CD40L, and the migration of PBMCs. In conclusion, elevated BCAA blood levels can promote the activation of circulating PBMCs, by a mechanism that involving ROS production and NF-κB pathway activation. These data suggest that high concentrations of BCAA could exert deleterious effects on circulating blood cells and therefore contribute to the pro-inflammatory and oxidative status observed in several pathophysiological conditions., (Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.)

We aimed to evaluate macrophages heterogeneity and structural, functional and inflammatory alterations in rat kidney by aldosterone + salt administration. The effects of treatment with spironolactone on above parameters were also analyzed. Male Wistar rats received aldosterone (1 mgkg-1d-1) + 1% NaCl for 3 weeks. Half of the animals were treated with spironolactone (200 mg kg-1d-1). Systolic and diastolic blood pressures were elevated (p<0.05) in aldosterone + salt-treated rats. Relative kidney weight, collagen content, fibronectin, macrophage infiltrate, CTGF, Col I, MMP2, TNF-α, CD68, Arg2, and SGK-1 were increased (p<0.05) in aldosterone + salt-treated rats, being reduced by spironolactone (p<0.05). Increased iNOS and IFN-γ mRNA gene expression (M1 macrophage markers) was observed in aldosterone + salt rats, whereas no significant differences were observed in IL-10 and gene ArgI mRNA expression or ED2 protein content (M2 macrophage markers). All the observed changes were blocked with spironolactone treatment. Macrophage depletion with liposomal clodronate reduced macrophage influx and inflammatory M1 markers (INF-γ or iNOS), whereas interstitial fibrosis was only partially reduced after this intervention, in aldosterone plus salt-treated rats. In conclusion, aldosterone + salt administration mediates inflammatory M1 macrophage phenotype and increased fibrosis throughout mineralocorticoid receptors activation.

Introduction: The nuclear factor-κB (NF-κB) is an important regulator of the inflammatory response. Angiotensin II (Ang II) activates the NF-κB pathway linked to renal inflammation. Although both AT1 and AT2 receptors are involved in Ang II-mediated NF-κB activation, the biological processes mediated by each receptor are not fully characterized. Interleukin-1β (IL-1β) is an important macrophage-derived cytokine that regulates immune and inflammatory processes, activating intracellular pathways shared with Ang II, including the NF-κB., Materials and Methods: In vitro studies were done in primary cultured rat mesangial cells. NF-κB pathway was evaluated by phosphorylated levels of p65/IκB and DNA binding activity. The Ang II receptor subtype was determined by pretreatment with AT1 and AT2 antagonists., Results: In mesangial cells the simultaneous presence of Ang II and IL-1β caused a synergistic activation of the NF-κB pathway and a marked upregulation of proinflammatory factors under NF-κB control, including monocyte chemoattractant protein-1. The AT1, but not AT2, antagonist abolished the synergistic effect on NF-κB activation and proinflammatory genes caused by coincubation of Ang II and IL-1β., Conclusions: These data indicates that Ang II, via AT1/NF-κB pathway activation, cooperates with IL-β to increase the inflammatory response in mesangial cells., (© The Author(s) 2014.)

Chronic activation of Janus kinase/signal transducers and activators of transcription (JAK/STAT) pathway contributes to vascular inflammation and atherosclerosis by inducing expression of genes involved in cell proliferation, differentiation and migration. We aimed to investigate whether enforced expression of negative regulators, the suppressors of cytokine signaling (SOCS1 and SOCS3), inhibits harmful JAK/STAT-mediated responses and affects atherosclerosis in apolipoprotein E knockout mice. Adenovirus-mediated SOCS1 transgene expression impaired the onset and progression of atherosclerosis without impact on lipid profile, whereas SOCS3 was only effective on early atherosclerosis. Mechanistically, SOCS gene delivery, primarily SOCS1, attenuated STAT1 and STAT3 activation and reduced the expression of STAT-dependent genes (chemokine/chemokine receptors, adhesion molecules, pro-inflammatory cytokines and scavenger receptors) in aortic tissue. Furthermore, atherosclerotic plaques exhibit a more stable phenotype characterized by lower lipids, T cells and M1 macrophages and higher M2 macrophages and collagen. Atheroprotection was accompanied by a systemic alteration of T helper- and T regulatory-related genes and a reduced activation state of circulating monocytes. In vascular smooth muscle cells and macrophages, SOCS gene delivery inhibited cytokine-induced STAT activation, pro-inflammatory gene expression, cell migration and proliferation. In conclusion, targeting SOCS proteins, predominantly SOCS1, to suppress pathological mechanisms involved in atheroma plaque progression and destabilization could be an interesting anti-atherosclerotic strategy.

Patients infected with the human immunodeficiency virus (HIV) have an increased cardiovascular risk. Although initially this increased risk was attributed to metabolic alterations associated with antiretroviral treatment, in recent years, the attention has been focused on the HIV disease itself. Inflammation, immune system activation, and endothelial dysfunction facilitated by HIV infection have been identified as key factors in the development and progression of atherosclerosis. In this review, we describe the epidemiology and pathogenesis of cardiovascular disease in patients with HIV infection and summarize the latest knowledge on the relationship between traditional and novel inflammatory, immune activation, and endothelial dysfunction biomarkers on the cardiovascular risk associated with HIV infection.

Chronic kidney disease is characterized by Vitamin D deficiency and activation of the renin-angiotensin-aldosterone system. Increasing data show that vitamin D receptor agonists (VDRAs) exert beneficial effects in renal disease and possess anti-inflammatory properties, but the underlying mechanism remains unknown. Emerging evidence suggests that "a disintegrin and metalloproteinase" (ADAM)/epidermal growth factor receptor (EGFR) signalling axis contributes to renal damage. Aldosterone induces EGFR transactivation regulating several processes including cell proliferation and fibrosis. However, data on tubular epithelial cells is scarce. We have found that, in cultured tubular epithelial cells, aldosterone induced EGFR transactivation via TGF-α/ADAM17. Blockade of the TGF-α/ADAM17/EGFR pathway inhibited aldosterone-induced proinflammatory gene upregulation. Moreover, among the potential downstream mechanisms, we found that TGF-α/ADAM17/EGFR inhibition blocked ERK and STAT-1 activation in response to aldosterone. Next, we investigated the involvement of TGF-α/ADAM17/EGFR axis in VDRA anti-inflammatory effects. Preincubation with the VDRA paricalcitol inhibited aldosterone-induced EGFR transactivation, TGF-α/ADAM-17 gene upregulation, and downstream mechanisms, including proinflammatory factors overexpression. In conclusion, our data suggest that the anti-inflammatory actions of paricalcitol in tubular cells could depend on the inhibition of TGF-α/ADAM17/EGFR pathway in response to aldosterone, showing an important mechanism of VDRAs action.

The CCN family member 2 (CCN2, also known as connective tissue growth factor) may behave as a risk biomarker and a potential therapeutic target for renal disease. CCN2 participates in the regulation of inflammation and fibrosis. TGF-β is considered the main fibrogenic cytokine; however, in some pathological settings TGF-β also has anti-inflammatory properties. CCN2 has been proposed as a downstream profibrotic mediator of TGF-β, but data on TGF-β role in CCN2 actions are scarce. Our aim was to evaluate the effect of TGF-β blockade in CCN2-mediated experimental renal damage. Systemic administration of the C-terminal module of CCN2 to mice caused sustained renal inflammation. In these mice, TGF-β blockade, using an anti-TGF-β neutralizing antibody, significantly increased renal expression of the NGAL (a kidney injury biomarker), kidney infiltration by monocytes/macrophages, and upregulation of MCP-1 expression. The anti-inflammatory effect of TGF-β seems to be mediated by a dysregulation of the systemic Treg immune response, shown by decreased levels of circulating CD4(+)/Foxp3(+)Treg cells. Our experimental data support the idea that TGF-β exerts anti-inflammatory actions in the kidney and suggest that it is not an optimal therapeutic target.

Objective: Activation of Janus kinase/signal transducers and activators of transcription (STAT) pathway by hyperglycemia and dislypidemia contributes to the progression of diabetic complications, including atherosclerosis. Suppressor of cytokine signaling (SOCS) proteins negatively regulate Janus kinase/STAT and have emerged as promising target for anti-inflammatory therapies. We investigated whether a cell-permeable lipopeptide corresponding to the kinase inhibitory region of SOCS1 could reduce atherosclerosis in diabetic mice and identified the mechanisms involved., Approach and Results: Streptozotocin-induced diabetic apolipoprotein E-deficient mice (aged 8 and 22 weeks) were given intraperitoneal injections of vehicle, SOCS1-derived peptide, or control mutant peptide for 6 to 10 weeks. SOCS1 therapy suppressed STAT1/STAT3 activation in atherosclerotic plaques of diabetic mice and significantly reduced lesion size at both early and advanced stages of lesion development compared with vehicle group. Plaque characterization demonstrated that SOCS1 peptide decreased the accumulation of lipids, macrophages, and T lymphocytes, whereas increasing collagen and smooth muscle cell content. This atheroprotective effect was accompanied by systemic (reduced proinflammatory Ly6C(high) monocytes and splenic cytokine expression) and local (reduced aortic expression of chemokines and cytokines) mechanisms, without impact on metabolic parameters. In vitro, SOCS1 peptide dose dependently inhibited STAT1/STAT3 activation and target gene expression in vascular smooth muscle cells and macrophages and also suppressed cytokine-induced cell migration and adhesion processes., Conclusions: SOCS1-based targeting Janus kinase/STAT restrains key mechanisms of atherogenesis in diabetic mice, thereby preventing plaque formation and increasing plaque stability. Approaches to mimic native SOCS1 functions may have a therapeutic potential to retard the progression of diabetic complications., (© 2014 American Heart Association, Inc.)

Non-proliferative proteinuric diseases are the most common primary glomerular disorders causing end-stage renal disease. These disorders may associate low level glomerular inflammation and podocyte expression of inflammatory mediators. However, the factors regulating podocyte expression of inflammatory mediators in vivo in non-immune disorders are poorly understood. We have now explored the regulation and role of TWEAK receptor Fn14 in mediating glomerular inflammation in cultured podocytes and in experimental and human non-immune proteinuria. Transcriptomics disclosed Fn14 and MCP-1 mRNA upregulation in glomeruli from patients with focal segmental glomerulosclerosis, as well as a correlation between the expression of both transcripts. Increased glomerular Fn14 and MCP-1 mRNA was confirmed in a second focal segmental glomerulosclerosis cohort and was also observed in membranous nephropathy. In human non-proliferative proteinuric kidney diseases podocytes displayed Fn14 and MCP-1 expression and NFκB activation. Podocyte Fn14 was increased in murine protein overload-induced proteinuria. In Fn14 knock-out mice with protein overload-induced proteinuria, glomerular and periglomerular macrophage infiltrates were reduced, as were MCP-1 mRNA and podocyte MCP-1 staining and podocyte numbers preserved as compared to wild-type counterparts. Adenovirus-mediated overexpression of TWEAK increased periglomerular macrophage infiltration in mice without prior kidney injury. In cultured podocytes inflammatory cytokines increased Fn14 mRNA and protein levels. TWEAK activated NFκB and increased MCP-1 mRNA and protein, an effect prevented by the NFκB inhibitor parthenolide. In conclusion, Fn14 activation results in NFκB-mediated pro-inflammatory effects on podocytes that may be relevant for the pathogenesis of non-proliferative proteinuric kidney disease of non-immune origin., (© 2013.)

The polyglutamic acid/peptoid 1 (QM56) nanoconjugate inhibits apoptosis by interfering with Apaf-1 binding to procaspase-9. We now describe anti-inflammatory properties of QM56 in mouse kidney and renal cell models.In cultured murine tubular cells, QM56 inhibited the inflammatory response to Tweak, a non-apoptotic stimulus. Tweak induced MCP-1 and Rantes synthesis through JAK2 kinase and NF-κB activation. Similar to JAK2 kinase inhibitors, QM56 inhibited Tweak-induced NF-κB transcriptional activity and chemokine expression, despite failing to inhibit NF-κB-p65 nuclear translocation and NF-κB DNA binding. QM56 prevented JAK2 activation and NF-κB-p65(Ser536) phosphorylation. The anti-inflammatory effect and JAK2 inhibition by QM56 were observed in Apaf-1(-/-) cells. In murine acute kidney injury, QM56 decreased tubular cell apoptosis and kidney inflammation as measured by down-modulations of MCP-1 and Rantes mRNA expression, immune cell infiltration and activation of the JAK2-dependent inflammatory pathway.In conclusion, QM56 has an anti-inflammatory activity which is independent from its role as inhibitor of Apaf-1 and apoptosis and may have potential therapeutic relevance.

End-stage renal disease patients suffer a syndrome of accelerated aging characterized by a 10- to 100-fold increase in cardiovascular and all-cause mortality when compared to age-matched controls. No specific therapeutic interventions have been shown to improve this dismal outcome. Inflammation, chronic kidney disease-mineral and bone disorder (CKD-MBD) and other biomarkers predict outcome in observational studies. However, we lack clinical trials that address the role of these biomarkers in risk stratification and therapeutic decision making. Biomarkers may also provide insights into the pathophysiology of disease and identify novel therapeutic targets. Inflammation emerges as a prime potential target for intervention. Thus, CKD-MBD biomarkers, asymmetrical dimethyl arginine and tri-iodothyronine have a link to inflammation. Interleukin-6 (IL-6) is one of the inflammation biomarkers with highest predictive value for outcome in ESRD. Biologicals targeting IL-6 are approved for the treatment of chronic inflammatory conditions such as rheumatoid arthritis. Furthermore, trials are underway to test IL-6 targeting potential to decrease cardiovascular injury in non-CKD patients. In this regard, targeting IL-1 was recently shown to decrease systemic inflammation in hemodialysis patients. The success of these trials will likely influence future studies on biomarker targeting in CKD.

Prevention and treatment of atherosclerosis is still a clinical challenge in the cardiovascular medicine. The classical belief that atherosclerotic lesion development solely depends on lipid deposition has been replaced by the current concept that activation of immune and inflammatory responses plays a central role in plaque initiation and progression. In this review we summarize studies on human and genetically modified animals describing a finite number of cellular and molecular mechanisms that underlie immunoinflammation in atherosclerotic plaques. We focus on the pro- and antiinflammatory mediators activated during atherogenesis and the intracellular signaling pathways regulating these events. Besides the advances on established pharmacological agents, we propose potential strategies for reduction/stabilization of atherosclerotic plaques based on the clinical data in inflammatory-associated pathologies and on the encouraging studies in experimental models of atherosclerosis. We emphasize the potential of such novel inhibitors comprising receptor antagonists, neutralizing antibodies, kinase inhibitors, peptide-based technologies, and chemicals as emerging antiinflammatory strategies for the treatment of atherosclerotic disease complications., (© 2011 Blackwell Publishing Ltd.)

Tumor necrosis factor-like weak inducer of apoptosis (TWEAK, TNFSF12) is a member of the tumor necrosis factor superfamily. TWEAK activates the Fn14 receptor, and may regulate cell death, survival and proliferation in tumor cells. However, there is little information on the function and regulation of this system in prostate cancer. Fn14 expression and TWEAK actions were studied in two human prostate cancer cell lines, the androgen-independent PC-3 cell line and androgen-sensitive LNCaP cells. Additionally, the expression of Fn14 was analyzed in human biopsies of prostate cancer. Fn14 expression is increased in histological sections of human prostate adenocarcinoma. Both prostate cancer cell lines express constitutively Fn14, but, the androgen-independent cell line PC-3 showed higher levels of Fn14 that the LNCaP cells. Fn14 expression was up-regulated in PC-3 human prostate cancer cells in presence of inflammatory cytokines (TNFα/IFNγ) as well as in presence of bovine fetal serum. TWEAK induced apoptotic cell death in PC-3 cells, but not in LNCaP cells. Moreover, in PC-3 cells, co-stimulation with TNFα/IFNγ/TWEAK induced a higher rate of apoptosis. However, TWEAK or TWEAK/TNFα/IFNγ did not induce apoptosis in presence of bovine fetal serum. TWEAK induced cell death through activation of the Fn14 receptor. Apoptosis was associated with activation of caspase-3, release of mitochondrial cytochrome C and an increased Bax/BclxL ratio. TWEAK/Fn14 pathway activation promotes apoptosis in androgen-independent PC-3 cells under certain culture conditions. Further characterization of the therapeutic target potential of TWEAK/Fn14 for human prostate cancer is warranted.

Objective: Atherosclerosis is prevalent in diabetic patients, but there is little information on the localization of nonesterified fatty acids (NEFAs) within the plaque and their relationship with inflammation. We sought to characterize the NEFA composition and location in human diabetic atheroma plaques by metabolomic analysis and imaging and to address their relationship with inflammation activity., Research Design and Methods: Time-of-flight secondary ion mass spectrometry (TOF-SIMS) was used for metabolomic analysis imaging of frozen carotid atheroma plaques. Carotid endarterectomy specimens were used for conventional immunohistochemistry, laser-capture microdissection quantitative PCR, and in situ Southwestern hybridization. Biological actions of linoleic acid were studied in cultured vascular smooth muscle cells (VSMCs)., Results: TOF-SIMS imaging evidenced a significant increase in the quantity of several NEFA in diabetic versus nondiabetic atheroma plaques. Higher levels of NEFA were also found in diabetic sera. The presence of LPL mRNA in NEFA-rich areas of the atheroma plaque, as well as the lack of correlation between serum and plaque NEFA, suggests a local origin for plaque NEFA. The pattern of distribution of plaque NEFA is similar to that of MCP-1, LPL, and activated NF-kappaB. Diabetic endarterectomy specimens showed higher numbers of infiltrating macrophages and T-lymphocytes-a finding that associated with higher NEFA levels. Finally, linoleic acid activates NF-kappaB and upregulates NF-kappaB-mediated LPL and MCP-1 expression in cultured VSMC., Discussion: There is an increased presence of NEFA in diabetic plaque neointima. NEFA levels are higher in diabetic atheroma plaques than in nondiabetic subjects. We hypothesize that NEFA may be produced locally and contribute to local inflammation.

Aims: Heat shock protein 90 (HSP90) is a ubiquitous chaperone involved in the folding, activation, and assembly of many proteins. HSP90 inhibitors [17-allylamino-17-demethoxygeldamycin (17-AAG)/17-dimethyl aminothylamino-17-demethoxygeldanamycin hydrochloride (17-DMAG)] bind to and inactivate HSP90, increasing the heat shock response and suppressing different signalling pathways. We aim to investigate the effect of HSP90 inhibitors in the modulation of inflammatory responses during atherogenesis., Methods and Results: In human atherosclerotic plaques, HSP90 immunostaining was increased in inflammatory regions and in plaques characterized by lower cap thickness. In cultured human macrophages and vascular smooth muscle cells, treatment with either 17-AAG or 17-DMAG increased HSP70 expression and reduced transcription factor [signal transducers and activators of transcription (STAT) and nuclear factor-kappaB (NF-kappaB)] activation and chemokine expression induced by proinflammatory cytokines. In vivo, hyperlipidaemic ApoE(-/-) mice were randomized to 17-DMAG (2 mg/kg every 2 days, n = 11) or vehicle injected (n = 9) during 10 weeks. Atherosclerotic plaques of mice treated with 17-DMAG displayed increased HSP70 expression and diminished NF-kappaB and STAT activation, along with decreased lesion, lipid, and macrophage content, compared with vehicle-injected mice. In addition, treatment with 17-DMAG significantly reduced monocyte chemoattractant protein-1 levels, both in plaques and in plasma., Conclusion: HSP90 expression is associated with features of plaque instability in advanced human lesions. HSP90 inhibitors reduce inflammatory responses in atherosclerosis, suggesting that HSP90 could be a novel therapeutic target in atherosclerosis.

The aim of this paper is to study the myocardial damage secondary to long-term streptozotocin-induced type 1 diabetes mellitus (DM1). Normotensive and spontaneously hypertensive rats (SHR) received either streptozotocin injections or vehicle. After 22 or 6 wk, DM1, SHR, DM1/SHR, and control rats were killed, and the left ventricles studied by histology, quantitative PCR, Western blot, ELISA, and electromobility shift assay. Cardiomyocyte cultures were also performed. The expression of profibrotic factors, transforming growth factor-beta (TGF-beta1), connective tissue growth factor, and matrix proteins was increased, and the TGF-beta1-linked transcription factors phospho-Smad3/4 and activator protein-1 were activated in the DM1 myocardium. Proapoptotic molecules FasL, Fas, Bax, and cleaved caspase-3 were also augmented. Myocardial injury in long-term hypertension shared these features. In addition, hypertension was associated with activation of NF-kappaB, increased inflammatory cell infiltrate, and expression of the mediators [interleukin-1beta (IL-1beta), tumor necrosis factor-alpha, monocyte chemoattractant protein 1, vascular cell adhesion molecule 1, angiotensinogen, and oxidants], which were absent in long-term DM1. At this stage, the combination of DM1 and hypertension resulted in nonsignificant additive effects. Moreover, the coexistence of DM1 blunted the inflammatory response to hypertension. Anti-inflammatory IL-10 and antioxidants were induced in long-term DM1 and DM1/SHR hearts. Myocardial inflammation was, however, observed in the short-term model. In cultured cardiomyocytes, IL-10, TGF-beta1, and catalase blocked the glucose-stimulated expression of proinflammatory genes. Fibrosis and apoptosis are features of long-term myocardial damage in experimental DM1. Associated hypertension does not induce additional changes. Myocardial inflammation is present in hypertension and short-term DM1, but is not a key feature in long-term DM1. Local reduction of proinflammatory factors and expression of anti-inflammatory and antioxidant molecules may underlie this effect.

Aims: The purpose of this study was to analyse the expression of CD74 in human atherosclerotic plaques and peripheral blood mononuclear cells (PBMC) as well as its potential participation in proinflammatory responses in cultured human vascular smooth muscle cells (VSMC)., Methods and Results: CD74 expression was analysed in human atherosclerotic plaques (immunohistochemistry), PBMC (real-time PCR), and human aortic VSMC (real-time PCR and western blotting). Nuclear factor-kappaB (NF-kappaB) activation was assessed by southwestern histochemistry and electrophoretic mobility shift assay. Monocyte chemoattractant protein-1 (MCP-1) levels were studied by both real-time PCR and enzyme-linked immunosorbent assay. CD74 immunostaining was increased in the inflammatory vs. the fibrous region of atherosclerotic plaques (n = 70, 18.2 +/- 1.3 vs. 7.8 +/- 0.6% positive staining/mm2, P < 0.001). CD74 colocalized with the transcription factor NF-kappaB in both VSMC and macrophages. In cultured VSMC, CD74 expression was induced by interferon gamma (IFNgamma). Incubation with an agonistic anti-CD74 antibody or with IFNgamma elicited MCP-1 expression, which was prevented by AKT and gamma-secretase inhibitors. Moreover, CD74 small-interfering RNA decreased NF-kappaB activation and MCP-1 production induced by IFNgamma in VSMC. Finally, CD74 mRNA levels in PBMC from patients with carotid stenosis were higher than in healthy subjects (n = 20, 3 +/- 0.5 vs. 2 +/- 0.5 AU, P < 0.001). Additionally, a linear trend between CD74 mRNA expression tertiles and intima-media thickness (IMT) was observed in PBMC from asymptomatic subjects (n = 185, P < 0.001)., Conclusion: CD74 levels are increased in plaques and PBMC from patients with carotid stenosis and are associated with IMT in subjects free from clinical cardiovascular diseases. CD74 could be a novel therapeutic target to decrease the inflammatory response in atherosclerosis.

Connective tissue growth factor (CTGF) is an important profibrotic factor in kidney diseases. Blockade of endogenous CTGF ameliorates experimental renal damage and inhibits synthesis of extracellular matrix in cultured renal cells. CTGF regulates several cellular responses, including adhesion, migration, proliferation, and synthesis of proinflammatory factors. Here, we investigated whether CTGF participates in the inflammatory process in the kidney by evaluating the nuclear factor-kappa B (NF-kappaB) pathway, a key signaling system that controls inflammation and immune responses. Systemic administration of CTGF to mice for 24 h induced marked infiltration of inflammatory cells in the renal interstitium (T lymphocytes and monocytes/macrophages) and led to elevated renal NF-kappaB activity. Administration of CTGF increased renal expression of chemokines (MCP-1 and RANTES) and cytokines (INF-gamma, IL-6, and IL-4) that recruit immune cells and promote inflammation. Treatment with a NF-kappaB inhibitor, parthenolide, inhibited CTGF-induced renal inflammatory responses, including the up-regulation of chemokines and cytokines. In cultured murine tubuloepithelial cells, CTGF rapidly activated the NF-kappaB pathway and the cascade of mitogen-activated protein kinases, demonstrating crosstalk between these signaling pathways. CTGF, via mitogen-activated protein kinase and NF-kappaB activation, increased proinflammatory gene expression. These data show that in addition to its profibrotic properties, CTGF contributes to the recruitment of inflammatory cells in the kidney by activating the NF-kappaB pathway.

Glucosamine sulfate (GS) is a glycosaminoglycan with anti-inflammatory and immunoregulatory properties. Here we set out to explore the effect of GS administration on markers of systemic and local inflammation in rabbits with atherosclerosis aggravated by chronic arthritis. Atherosclerosis was induced in rabbits by maintaining them on a hyperlipidemic diet after producing an endothelial lesion in the femoral arteries. Simultaneously, chronic arthritis was induced in these animals by repeated intra-articular injections of ovalbumin in previously immunized rabbits. A group of these rabbits was treated prophylactically with oral GS (500 mg.kg(-1).day(-1)), and, when the animals were killed, serum was extracted and peripheral blood mononuclear cells (PBMC) were isolated. Furthermore, the femoral arteries, thoracic aorta, and synovial membranes were examined in gene expression studies and histologically. GS administration reduced circulating levels of the C-reactive protein and of interleukin-6. GS also lowered nuclear factor-kappaB activation in PBMC, and it downregulated the expression of both the CCL2 (monocyte chemoattractant protein) and cyclooxygenase-2 genes in these cells. Lesions at the femoral wall were milder after GS treatment, as reflected by the intimal-to-media thickened ratio and the absence of aortic lesions. Indeed, GS also attenuated the histological lesions in synovial tissue. In a combined rabbit model of chronic arthritis and atherosclerosis, orally administered GS reduced the markers of inflammation in peripheral blood, as well as the femoral and synovial membrane lesions. GS also prevented the development of inflammation-associated aortic lesions. These results suggest an atheroprotective effect of GS.

Background: Inflammation is crucial in all stages of atherosclerosis, and few studies have investigated the effect of dietary fat on markers of inflammation related to this disease during the postprandial period., Objective: To evaluate the chronic effects of dietary fat on the postprandial expression of proinflammatory genes in peripheral blood mononuclear cells (PBMCs) in healthy subjects., Design: 20 healthy men followed three different diets for 4 weeks each, according to a randomized crossover design: Western diet: 15% protein, 47% carbohydrates (CHO), 38% fat (22% saturated fatty acid (SFA)); Mediterranean diet: 15% protein, 47% CHO, 38% fat (24% monounsaturated fatty acid (MUFA)); CHO-rich and n-3 diet: 15% protein, 55% CHO, <30% fat (8% polyunsaturated fatty acid (PUFA)). After 12-h fast, volunteers were given a breakfast with a fat composition similar to that consumed in each of the diets-butter breakfast: 35% SFA; olive oil breakfast: 36% MUFA; walnut breakfast: 16% PUFA, 4% alpha-linolenic acid (LNA)., Results: The butter breakfast induced a higher increase in tumor necrosis factor (TNF)-alpha messenger RNA (mRNA) expression than the olive oil or walnut breakfasts (P=0.014) in PBMCs. Moreover, we found a higher postprandial response in the mRNA of interleukin (IL)-6 with the intake of butter and olive oil breakfasts than with the walnut breakfast (P=0.025) in these cells. However, the effects of the three fatty breakfasts on the plasma concentrations of these proinflammatory parameters showed no significant differences (P=N.S.)., Conclusion: Consumption of a butter-enriched meal elicits greater postprandial expression of proinflammatory cytokine mRNA in PBMCs, compared to the olive oil and walnut breakfasts.

Angiotensin (Ang) II mediates pathophysiologial changes in the kidney. Ang-(1-7) by interacting with the G protein-coupled receptor Mas may also have important biological activities.In this study, renal deficiency for Mas diminished renal damage in models of renal insufficiency as unilateral ureteral obstruction and ischemia/reperfusion injury while the infusion of Ang-(1-7) to wild-type mice pronounced the pathological outcome by aggravating the inflammatory response. Mas deficiency inhibited NF-kappaB activation and thus the elevation of inflammation-stimulating cytokines, while Ang-(1-7) infusion had proinflammatory properties in experimental models of renal failure as well as under basal conditions. The Ang-(1-7)-mediated NF-kappaB activation was Mas dependent but did not involve Ang II receptors. Therefore, the blockade of the NF-kappaB-activating properties of the receptor Mas could be a new strategy in the therapy of failing kidney.

Background and Objectives: Chronic kidney disease (CKD) is characterized by an exceptionally high mortality rate, primarily due to cardiovascular disease. Reduced soluble TNF-like weak inducer of apoptosis (sTWEAK) plasma levels have been reported both in patients with subclinical atherosclerosis and CKD., Design, Participants, & Measurements: A cross-sectional study was conducted in 218 prevalent patients (121 men; 63 +/- 14 yr) undergoing hemodialysis (HD). sTWEAK levels in relation with the patients' outcome were studied., Results: sTWEAK plasma levels were 208 [(165 to 272) pg/ml, median interquartile range], significantly lower than healthy controls (P < 0.0001). sTWEAK was negatively associated with inflammatory markers, such as C-reactive protein and IL-6. Overall mortality was assessed after an average follow-up of 31 mo, during which 81 patients died. After controlling for potential confounding variables, patients in the upper tertile of sTWEAK plasma levels had an increased risk of cardiovascular and all-cause mortality. A significant interaction effect between sTWEAK and IL-6 levels was found [synergy index: 2.19 (0.80, 5.93)]. Thus, the association of sTWEAK with mortality was strongest in patients with inflammation (defined as IL-6 > 7.0 pg/ml), in whom high sTWEAK strongly predicted cardiovascular and all-cause mortality. These results were confirmed in a second cohort of HD patients., Conclusions: The concurrent presence of elevated sTWEAK plasma concentrations and an inflammatory environment have additive effects on mortality in HD patients. Further studies on the potential different role of sTWEAK in health and disease are warranted.

The CD40/CD40 ligand plays a role in the inflammatory and prothrombotic processes in atherosclerosis. We analyzed whether short-term treatment with atorvastatin affects soluble CD40 ligand (sCD40L) plasma levels in subjects at high cardiovascular risk. sCD40L plasma concentrations were measured in 852 subjects from the Atorvastatin on Inflammatory Markers (AIM) Study, a 12-week prospective multicenter, open-label trial which enrolled statin-free subjects with coronary heart disease (CHD), CHD-equivalent (diabetes, peripheral vascular disease, or cerebrovascular disease), or a 10-year CHD risk >20%. Subjects were assigned to atorvastatin (10-80 mg/day) based on LDL-C at screening. Overall, sCD40L levels were not different in patients at high cardiovascular risk compared with healthy subjects. When sCD40L levels were divided in quartiles, patients in the highest quartile (N=213) had higher sCD40L concentrations than age- and gender-matched healthy subjects (N=29) (P<0.0001). Interestingly, all doses of atorvastatin significantly diminished sCD40L levels in subjects at the highest quartile. Furthermore, atorvastatin treatment decreased sCD40L more markedly in subjects with metabolic syndrome compared with those without metabolic syndrome. In conclusion, atorvastatin diminishes sCD40L plasma levels, more markedly so in subjects with metabolic syndrome. Our results indicate that short-term treatment with atorvastatin exhibits anti-inflammatory and antithrombotic effects in subjects at high cardiovascular risk.

Objective: To determine whether systemic inflammation induced by chronic antigen-induced arthritis (AIA) accelerates vascular lesions in rabbits with atherosclerosis., Methods: Two models of atherosclerosis and chronic AIA were combined. Atherosclerosis was induced by coupling a hyperlipemic diet with an endothelial lesion at the femoral arteries, while chronic AIA was induced by ovalbumin injection. Markers in sera and peripheral blood mononuclear cells (PBMCs) as well as vessels and synovial membranes from the rabbits with the double phenotype (both chronic AIA and atherosclerosis) were compared with those from rabbits with each disease alone., Results: Serum levels of interleukin-6, C-reactive protein, and prostaglandin E(2) increased in rabbits with both chronic AIA and atherosclerosis as compared with healthy animals or animals with either chronic AIA alone or atherosclerosis alone. NF-kappaB binding and CCL2 and cyclooxygenase 2 (COX-2) expression were higher in PBMCs from rabbits with both chronic AIA and atherosclerosis than in PBMCs from healthy rabbits. The intima-media thickness ratio of femoral arteries was equally increased in rabbits with atherosclerosis alone and in rabbits with both chronic AIA and atherosclerosis, but the latter group showed a higher level of macrophage infiltration. Femoral CCL2 and COX-2 expression was increased in rabbits with both chronic AIA and atherosclerosis as compared with rabbits with atherosclerosis alone. In the aortas, vascular lesions were found in 27% of rabbits with atherosclerosis alone and in 60% of rabbits with both chronic AIA and atherosclerosis. Rabbits with both chronic AIA and atherosclerosis exhibited more severe synovitis and higher synovial expression of CCL2 than did rabbits with chronic AIA alone., Conclusion: The onset of chronic AIA in animals with atherosclerosis resulted in the local and systemic up-regulation of mediators of tissue inflammation and plaque instability associated with a higher incidence of aortic lesions. This model could represent a novel approach to the study of inflammation-associated atherosclerosis.

Objective: Activation of transcription factor NF-kappaB is an important step in the development of vascular damage, because it controls inducible genes, including many inflammatory mediators. The pharmacological modulation of this process is the main objective in the design of new therapies for atherosclerosis. In this work we analyzed the effects of the natural compound parthenolide (PTN), an NF-kappaB inhibitor., Methods and Results: In vascular smooth muscle cells (VSMCs) and monocytes stimulated with lipopolysaccharide (LPS), nontoxic doses of PTN reduced IkappaBalpha degradation, NF-kappaB activation, and MCP-1 expression, without inhibiting AP-1 and MAPK. In apoE mice, treatment with low (2 mg/kg, 20 weeks), medium (4 mg/kg, 10 weeks), and high (10 mg/kg, 10 weeks) dose of PTN reduced the size of aortic lesion, decreased macrophage, and increased VSMC content in the lesions. Treated mice showed reduced serum levels of MCP-1 and attenuated NF-kappaB activity, but not AP-1, in the lesions. Moreover, PTN affects neither apoptotic cell death nor oxidative stress in cultured cells and mice., Conclusions: NF-kappaB inhibition by PTN retards atherosclerotic lesions in apoE mice, by reducing lesion size and changing plaque composition. This natural compound could represent a novel therapeutic approach to inflammation during vascular damage.

Purpose of Review: We will focus on the recent findings concerning the inflammatory response in vascular and renal tissues caused by hypertension., Recent Findings: Angiotensin II is one of the main factors involved in hypertension-induced tissue damage. This peptide regulates the inflammatory process. Angiotensin II activates circulating cells, and participates in their adhesion to the activated endothelium and subsequent transmigration through the synthesis of adhesion molecules, chemokines and cytokines. Among the intracellular signals involved in angiotensin II-induced inflammation, the production of reactive oxygen species and the activation of nuclear factor-kappaB are the best known., Summary: The pharmacological blockade of angiotensin II actions, by angiotensin-converting enzyme inhibitors or angiotensin receptor antagonists, results in beneficial organ protective effects, in addition to the effects of these agents on blood pressure control, that can be explained by the blockade of the angiotensin II-induced pro-inflammatory response. These data provide a rationale for the use of blockers of the renin-angiotensin system to prevent vascular and renal inflammation in patients with hypertension.

Background and Purpose: To investigate the effect of short-term high-dose atorvastatin on blood and plaque inflammation in patients with carotid stenosis., Methods: Twenty patients undergoing carotid endarterectomy without previous statin treatment were randomized to receive either atorvastatin 80 mg/d (n=11) or no statins (n=9) for 1 month. We studied inflammatory mediators in plasma (enzyme-linked immunosorbent assay), peripheral blood mononuclear cells (PBMCs; quantitative RT-PCR and EMSA) and plaques (immunohistochemistry and Southwestern histochemistry)., Results: Atorvastatin significantly decreased total and low-density lipoprotein cholesterol and prostaglandin E2 plasma levels. PBMCs from treated patients showed impaired NF-kappaB activation and MCP-1 and COX-2 mRNA expression. Carotid atherosclerotic plaques demonstrated a significant reduction in macrophage infiltration, activated NF-kappaB, and COX-2 and MCP-1 expression., Conclusions: Intensive treatment with atorvastatin decreases inflammatory activity of PBMCs and carotid atherosclerotic plaques in 1 month. These data strongly suggest that the antiinflammatory effect of high doses of statins in humans can be seen very early.

Inflammatory cell infiltration plays a key role in the onset and progression of renal injury. The NF-kappaB participates in the inflammatory response, regulating many proinflammatory genes. Angiotensin II (Ang II), via AT(1) and AT(2) receptors, activates NF-kappaB. Although the contribution of Ang II to kidney damage progression is already established, the receptor subtype involved in the inflammatory cell recruitment is not clear. For investigating this issue, the unilateral ureteral obstruction (UUO) model was used in mice, blocking Ang II production/receptors and NF-kappaB pathway. Two days after UUO, obstructed kidneys of wild-type mice presented a marked interstitial inflammatory cell infiltration and increased NF-kappaB activity. Treatment with AT(1) or AT(2) antagonists partially decreased NF-kappaB activation, whereas only the AT(2) blockade diminished monocyte infiltration. Obstructed kidneys of AT(1)-knockout mice showed interstitial monocyte infiltration and NF-kappaB activation; both processes were abolished by an AT(2) antagonist, suggesting AT(2)/NF-kappaB involvement in monocyte recruitment. In wild-type mice, only angiotensin-converting enzyme inhibition or combined therapy with AT(1) plus AT(2) antagonists blocked monocyte infiltration, NF-kappaB activation, and upregulation of NF-kappaB-related proinflammatory genes. Therefore, AT(1) and AT(2) blockade is necessary to arrest completely the inflammatory process. Treatment with two different NF-kappaB inhibitors, pirrolidin-dithiocarbamate and parthenolide, diminished monocyte infiltration and gene overexpression. These data show that Ang II, via AT(1) and AT(2) receptors and NF-kappaB pathway, participates in the regulation of renal monocyte recruitment and may provide a rationale to investigate further the role of AT(2) in human kidney diseases.

Angiotensin II (AngII), the major effector peptide of renin-angiotensin system (RAS), is now recognized as a growth factor that regulates cell growth and fibrosis, besides being a physiological mediator restoring circulatory integrity. In the last few years, a large number of experimental studies has further demonstrated that AngII is involved in key events of the inflammatory process. Here, we summarize the wide variety of AngII functions and discuss them in relation with the inflammatory cascade. AngII increases vascular permeability (via the release of prostaglandins and vascular endothelial cell growth factor or rearrangement of cytoskeletal proteins) that initiates the inflammatory process. AngII could contribute to the recruitment of inflammatory cells into the tissue through the regulation of adhesion molecules and chemokines by resident cells. Moreover, AngII could directly activate infiltrating immunocompetent cells, including chemotaxis, differentiation and proliferation. Recent data also suggest that RAS activation could play a certain role even in immunologically-induced inflammation. Transcriptional regulation, predominantly via nuclear factor-kappaB (NF-kappaB) and AP-1 activation, and second mediator systems, such as endothelin-1, the small G protein (Rho) and redox-pathways are shown to be involved in the molecular mechanism by which AngII exerts those functions. Finally, AngII participates in tissue repair and remodeling, through the regulation of cell growth and matrix synthesis. In summary, recent data support the hypothesis that RAS is key mediator of inflammation. Further understanding of the role of the RAS in this process may provide important opportunities for clinical research and treatment of inflammatory diseases.

Many experimental data have suggested that the renin-angiotensin system participates in immune and inflammatory responses. Angiotensin II is involved in several steps of the inflammatory process: mononuclear cells respond to angiotensin II stimulation (cell proliferation and chemotaxis); angiotensin II regulates the recruitment of proinflammatory cells into the site of injury (mediated by the expression of vascular permeability factors, adhesion molecules and chemokines by resident cells); inflammatory cells can produce angiotensin II, and might therefore contribute to the perpetuation of tissue damage. In this review, we summarize the proinflammatory properties of angiotensin II, to demonstrate the novel role of this vasoactive peptide as a true cytokine. We will show the information obtained as a result of the pharmacological blockade of the renin angiotensin system, which has demonstrated that this system is involved in immune and inflammatory diseases. In this aspect, we discuss the molecular mechanism of angiotensin II-induced tissue damage, as well as its contribution to the pathogenesis of several diseases, including atherosclerosis, hypertension and renal damage, showing that angiotensin II plays an active role in the inflammatory response of these diseases.

Clinical and basic research has increased our knowledge of the actions of the vasoactive hormone angiotensin II (Ang II), showing that it has multifunctional properties beyond its hemodynamic effects. It is commonly accepted that Ang II is a growth factor that participates in pathological settings, including renal diseases. However, a new aspect of this peptide is coming into focus: its potential role as a proinflammatory modulator. In this review, we summarize the apparently confusing information about the properties of Ang II and discuss its relations to the inflammatory process, as well as the potential mechanisms mediated by activation of nuclear transcription factors. Ang II seems to participate in the key events of the inflammatory response: First, it increases vascular permeability (via prostaglandins and vascular endothelial cell growth factor/vascular permeability factor) thus initiating the inflammatory process. Second, it participates in the recruitment of infiltrating cells into the tissues through direct activation of the inflammatory cells or by regulation of the expression of adhesion molecules and chemokines by resident cells. Finally, Ang II may contribute to tissue repair by regulation of cell growth and matrix synthesis. The renin-angiotensin system (RAS) thus appears to serve as a vascular inflammatory regulator and may even participate in immunologically-induced inflammation. However, more often activation of the RAS has an undesirable outcome, such as overhealing, because the inflammatory repair response itself involves a functionally imperfect system.

In this paper we have examined the cooperation between TNF and PAF in the generation of superoxide anion (O2-) in vitro by polymorphonuclear cells (PMNs), as well as their ability to induce joint inflammation when injected into the knee of healthy rabbits. TNF and PAF directly stimulated the generation of a small amount of O2- by PMNs. TNF pretreatment of PMNs induced a certain synergy in the O2- production, when these cells were later stimulated with PAF. When PAF receptor antagonists were added, the O2- release was inhibited. The injection of either TNF or PAF into the knee joint of normal rabbits induced a dose-dependent accumulation of leukocytes in the synovial cavity 24 h after administration. When TNF was administered 1 h before PAF, a synergistic response in the accumulation of leukocytes in the joint fluid was noted. The administration of BN 52726 by the intraperitoneal route markedly inhibited the cell accumulation induced by TNF and PAF. Histological signs of inflammation were noted in the synovial lining of joints injected with TNF and PAF. These results suggest that TNF can amplify the inflammatory response induced by PAF. PAF antagonists can inhibit this effect and thus may be of therapeutic value in different pathological situations.

Background: Abnormalities of mineral metabolism and inflammation may affect the cardiovascular system. We have assessed the relationship of left ventricular hypertrophy (LVH) with inflammation and mineral metabolism. Methods: LVH was measured in 146 outpatients with stable coronary artery disease (SCAD) using echocardiography. Calcidiol (a vitamin D metabolite), parathyroid hormone (PTH), fibroblast growth factor-23, high-sensitivity C-reactive protein, MCP-1 (monocyte chemoattractant protein-1), galectin-3, NGAL (neutrophil gelatinase-associated lipocalin), and sTWEAK (soluble TNF-related weak inducer of apoptosis) plasma levels were studied. Results: LVH, defined as septal thickness ≥11 mm, was present in 19.9% of cases. These patients were older [75.0 (61.0-81.0) vs 64.0 (51.0-76.0) years; p=0.002], had higher prevalence of left ventricular ejection fraction (LVEF)>40%, and had higher PTH [84.7 (59.6-104.7) vs 63.2 (49.2-85.2) pg/ml; p=0.007], galectin-3 [9.6 (8.0-11.1) vs 8.3 (6.9-9.9) ng/ml; p=0.037], and NGAL (208.5±87.6 vs 173.9±73.4 ng/ml; p=0.031) plasma levels than those without LVH. Glomerular filtration rate was lower in patients with LVH than in those without it (65.1±20.0 vs 74.7±19.9 mL/min/1.73 m; p=0.021). There were no significant differences in hypertension (79.3 vs 68.4%; p=0.363) or sex between both groups. Variables showing differences based on univariate analysis and hypertension were entered into a logistic regression analysis. Only age [odds ratio (OR) =1.052 (1.011-1.096); p=0.013], PTH plasma levels [OR=1.017 (1.003-1.031); p=0.021], and LVEF>40% [OR=7.595 (1.463-39.429); p=0.016] were independent predictors of LVH. Conclusions: In patients with SCAD, elevated PTH levels are independently associated with the presence of LVH. Further studies are needed to elucidate the role of PTH in the development of myocardial hypertrophy. [ABSTRACT FROM AUTHOR]

Diabetic cardiomyopathy entails a serious cardiac dysfunction induced by alterations in structure and contractility of the myocardium. This pathology is initiated by changes in energy substrates and occurs in the absence of atherothrombosis, hypertension, or other cardiomyopathies. Inflammation, hypertrophy, fibrosis, steatosis, and apoptosis in the myocardium have been studied in numerous diabetic experimental models in animals, mostly rodents. Type I and type II diabetes were induced by genetic manipulation, pancreatic toxins, and fat and sweet diets, and animals recapitulate the main features of human diabetes and related cardiomyopathy. In this review we update and discuss the main experimental models of diabetic cardiomyopathy, analysing the associated metabolic, structural, and functional abnormalities, and including current tools for detection of these responses. Also, novel experimental models based on genetic modifications of specific related genes have been discussed. The study of specific pathways or factors responsible for cardiac failures may be useful to design new pharmacological strategies for diabetic patients. [ABSTRACT FROM AUTHOR]

Diabetic cardiomyopathy is defined as a ventricular dysfunction initiated by alterations in cardiac energy substrates in the absence of coronary artery disease and hypertension. Hyperglycemia, hyperlipidemia, and insulin resistance are major inducers of the chronic low-grade inflammatory state that characterizes the diabetic heart. Cardiac Toll-like receptors and inflammasome complexes may be key inducers for inflammation probably through NF-κB activation and ROS overproduction. However, metabolic dysregulated factors such as peroxisome proliferator-activated receptors and sirtuins may serve as therapeutic targets to control this response by mitigating both Toll-like receptors and inflammasome signaling. [ABSTRACT FROM AUTHOR]

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Background and Purpose: Among the agents employed to manage osteoarthritis, chondroitin sulphate (CS) is a natural glycosaminoglycan with an anti-inflammatory effect on joint cells. CS might also influence the inflammatory component of atherosclerosis. Our aim was to examine the effect of CS administration on vascular injury and on markers of systemic inflammation in a rabbit model of atherosclerosis aggravated by systemic inflammation provoked by chronic antigen-induced arthritis.Experimental Approach: Atherosclerosis was induced in rabbits by maintaining them on a hyperlipidaemic diet after producing an endothelial lesion in the femoral arteries. Simultaneously, chronic arthritis was induced in these animals by repeated intraarticular injections of ovalbumin in previously immunized rabbits. A group of these rabbits were treated prophylactically with CS (100 mg kg(-1)day(-1)) and when the animals were killed, serum and peripheral blood mononuclear cells (PBMC) were isolated. Furthermore, femoral arteries and thoracic aorta were used for gene expression studies and histological examination.Key Results: CS administration reduced the concentration of the proinflammatory molecules C-reactive protein and IL-6 in serum. Likewise, CS inhibited the expression of CCL2/monocyte chemoattractant protein (MCP)-1 and cyclooxygenase (COX)-2 in PBMC, and reduced the nuclear translocation of nuclear factor-kappaB. In the femoral lesion, CS also diminished the expression of CCL2 and COX-2, as well as the ratio of the intima/media thickness. Moreover, CS decreased the percentage of rabbits with atherosclerosis and chronic arthritis that developed vascular lesions in the aorta.Conclusions and Implications: These findings suggest that CS treatment may to some extent impede the progression of atherosclerosis. [ABSTRACT FROM AUTHOR]