Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Inflammatory pathways”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 55 records · Page 3Linked to original sources

Activation of apoptotic and inflammatory pathways in dysfunctional donor hearts.

BACKGROUND: Myocardial dysfunction is common after brain death, but the mechanisms remain unclear. Apoptosis is tightly regulated by enzymes termed the caspases. We have investigated the caspases involved in the terminal part of the apoptotic pathway in dysfunctional (nontransplanted) donor hearts and their relation to inflammatory markers and compared them to hearts with good ventricular function (transplanted donors). METHODS: Thirty-one donor hearts assessed for transplantation were examined. Western blotting was used to measure pro-caspase-9, caspase-3, DFF45, the activated nuclease CPAN and poly (ADP-ribose) polymerase, a DNA repair enzyme inactivated by caspase-3. Caspase-3 activity was also measured. Histologic and immunocytochemical analysis for HLA Class II and Real Time polymerase chain reaction for tumor necrosis factor-alpha and interleukin 6 were performed to detect inflammatory activation. RESULTS: Cleaved caspase-9 was higher (5.53+/-0.6 vs. 3.64+/-0.4 O.D. units, P<0.01) in nontransplanted compared with transplanted donors and there was a trend for higher pro-caspase-9 (5.20+/-1.0 vs. 4.22+/-0.4 O.D. units, P=NS). Levels of pro-caspase-3 were higher in nontransplanted (9.66+/-0.5 vs. 5.15+/-0.5 O.D. units, P<0.00001) donors and cleavage products of caspase-3 were elevated in 14 of 14 nontransplanted and 2 of 17 transplanted donors. Intact DFF-45 (8.94+/-0.36 vs. 6.14+/-0.30 O.D. units, P<0.000005), its spliced product (2.38+/-0.35 vs. 0.4+/-0.21 O.D. units, P=0.0001) and the nuclease caspase-activated nuclease (2.01+/-0.3 vs. 0.66+/-0.16 OD units, P=0.001) were higher in nontransplanted donors. The caspase-3 substrate poly (ADP-ribose) polymerase was higher in nontransplanted (1.16+/-0.13 vs. 0.61+/-0.22 O.D. units, P=0.57) donors. CONCLUSIONS: The caspases are elevated in dysfunctional donor hearts compared with hearts with good ventricular function with a possible link to inflammatory activation supporting the concept that brain death causes inflammatory activation which can lead to apoptosis with a possible important effect on function.

Adult↗

Co-ordinate but disproportionate activation of apoptotic, regenerative and inflammatory pathways characterizes the liver response to acute amebic infection.

The liver has the remarkable ability to respond to injury with repair and regeneration. The protozoan parasite Entamoeba histolytica is the major cause of liver abscess worldwide. We report a transcriptional analysis of the response of mouse liver to E. histolytica infection, the first study looking at acute liver infection by a non-viral pathogen. Focusing on early time points, we identified 764 genes with altered transcriptional levels in amebic liver abscess. The response to infection is rapid and complex, with concurrent increased expression of genes linked to host defence through IL-1, TLR2, or interferon-induced pathways, liver regeneration via activation of IL-6 pathways, and genes associated with programmed cell death possibly through TNFalpha or Fas pathways. A comparison of amebic liver infection with the liver response to partial hepatectomy or toxins reveals striking similarities between amebic liver abscess and non-infectious injury in key components of the liver regeneration pathways. However, the response in amebic liver abscess is biased towards apoptosis when compared with acute liver injury from hepatectomy, toxins, or other forms of liver infection. E. histolytica infection of the liver simultaneously activates inflammatory, regenerative and apoptotic pathways, but the sum of these early responses is biased towards programmed cell death.

Animals↗

TNF&#x3b1;-dependent modulation of WT1-MMP9 regulatory axis links developmental and inflammatory pathways in glaucoma.

Glaucomas are heterogeneous optic neuropathies associated with extracellular matrix dysregulation, abnormal ocular morphogenesis, and inflammatory signaling. Targeted deep sequencing of 586 primary congenital glaucoma (PCG) cases and 1,757 controls identified rare pathogenic variants in multiple genes, including WT1 and MMP9. Notably, WT1 variants clustered within the nuclear export sequence. Further, functional analyses showed that combined wt1-pax6 suppression in zebrafish disrupted ocular morphogenesis, highlighting developmental interdependence. In human trabecular meshwork cells, WT1 acted as a transcriptional repressor of MMP9, while TNF-&#x3b1; signaling triggered nitric oxide-dependent nuclear export of WT1, resulting in delayed MMP9 upregulation. This effect was reversible by inhibiting nuclear export or nitric oxide synthase. A patient-derived mutation in the nuclear-export region of WT1, disrupted this regulatory switch, causing abnormal MMP9 expression. These findings position WT1 as an important regulator linking developmental and inflammatory mechanisms in glaucoma pathogenesis.

anterior segment dysgenesis↗

Anti-inflammatory pathways as a host evasion mechanism for pathogens.

Lipoxins play a key role in controlling potent pro-inflammatory responses triggered by infection with pathogens, such as Toxoplasma gondii and Mycobacterium tuberculosis. In order to contain microbial dissemination, infected hosts must mount a powerful immune response to prevent mortality. The onset of the chronic phase of infection is characterized by continuous cell-mediated immunity. Such potent responses are kept under tight control by a class of anti-inflammatory eicosanoids, the lipoxins. Here, we review such immune-containment strategies from the host's perspective, to keep pro-inflammatory responses under control during chronic disease, as well as from the perspective of the pathogen, which pirates the host's lipoxygenase machinery to its own advantage as a probable immune-escape mechanism.

Animals↗

Genetic evidence for repurposing GLP-1 receptor agonists in chronic kidney disease and IgA nephropathy: Metabolic and anti-inflammatory pathways beyond glycaemic control.

AIMS: Despite observational links between glucagon-like peptide-1 receptor agonists (GLP-1RAs) and kidney benefits, causal mechanisms remain unclear. This study aims to dissect genetic causality and mediation pathways underlying the effects of GLP-1RAs on chronic kidney disease (CKD) and related renal outcomes. MATERIALS AND METHODS: Using large-scale Genome - Wide Association Study (GWAS) data, we applied two-sample Mendelian randomisation (MR) to estimate the causal effects of GLP-1RAs on CKD, estimated glomerular filtration rate (eGFR) and subtypes (IgA nephropathy, membranous nephropathy, nephrotic syndrome and chronic glomerulonephritis), with sensitivity analyses. The glycaemic markers (glycated haemoglobin [HbA1c] and blood glucose), type 2 diabetes mellitus (T2DM) and diabetic nephropathy (DN) served as positive controls. Mediation MR assessed body mass index (BMI), lipids, glycaemic markers and inflammatory proteins. Data were sourced from MRC Integrative Epidemiology Unit Open Genome - Wide Association Studies OpenGWAS, FinnGen, GWAS Catalogue and cohort-specific studies. RESULTS: Positive control analyses revealed that genetically predicted GLP-1R activation was associated with reduced levels of HbA1c (p&#x2009;=&#x2009;4.93E-15) and blood glucose (p&#x2009;=&#x2009;9.73E-5), as well as a decreased risk of T2DM (p&#x2009;=&#x2009;2.45E-4) and DN (p&#x2009;=&#x2009;6.35E-4), fully validating the reliability of the genetic instruments. Genetic proxies for GLP-1R activation lowered risks of CKD (odds ratio [OR]&#x2009;=&#x2009;0.83, p&#x2009;=&#x2009;9.22E-9), immunoglobulin A nephropathy (IgAN) (OR&#x2009;=&#x2009;0.70, p&#x2009;=&#x2009;2.11E-3) and kidney function preservation (&#x3b2;&#x2009;=&#x2009;0.01, p&#x2009;=&#x2009;9.11E-3), but showed null effects on other CKD subtypes. Mediation analyses indicated that fibroblast growth factor 23 (FGF23) suppression mediated 26.57% of the effect on eGFR and 13.50% of CKD protection, whereas metabolic traits (BMI: 2.08% for CKD, 5.51% for eGFR; high-density lipoprotein: 0.79% for CKD, 2.34% for eGFR; HbA1c: 8.25% for eGFR) partially explained the benefits on CKD and eGFR. Only BMI exhibited a mediation effect on IgAN. Sensitivity analyses confirmed minimal pleiotropy. CONCLUSIONS: This study provides robust genetic evidence for repurposing GLP-1RAs in CKD and IgAN through anti-inflammatory (FGF23) and metabolic pathways, extending their utility beyond glucose control. While European ancestry data limit generalisability, our framework prioritises FGF23 and metabolic modulation as key targets for clinical trials in renal protection.

Humans↗

Endogenous lipid- and peptide-derived anti-inflammatory pathways generated with glucocorticoid and aspirin treatment activate the lipoxin A4 receptor.

Aspirin (ASA) and dexamethasone (DEX) are widely used anti-inflammatory agents yet their mechanism(s) for blocking polymorphonuclear neutrophil (PMN) accumulation at sites of inflammation remains unclear. Here, we report that inhibition of PMN infiltration by ASA and DEX is a property shared by aspirin-triggered lipoxins (ATL) and the glucocorticoid-induced annexin 1 (ANXA1)-derived peptides that are both generated in vivo and act at the lipoxin A(4) receptor (ALXR/FPRL1) to halt PMN diapedesis. These structurally diverse ligands specifically interact directly with recombinant human ALXR demonstrated by specific radioligand binding and function as well as immunoprecipitation of PMN receptors. In addition, the combination of both ATL and ANXA1-derived peptides limited PMN infiltration and reduced production of inflammatory mediators (that is, prostaglandins and chemokines) in vivo. Together, these results indicate functional redundancies in endogenous lipid and peptide anti-inflammatory circuits that are spatially and temporally separate, where both ATL and specific ANXA1-derived peptides act in concert at ALXR to downregulate PMN recruitment to inflammatory loci.

Animals↗

JNK: bridging the insulin signaling and inflammatory pathway.

Obesity and insulin resistance are strongly associated with systemic markers of inflammation and endoplasmic reticulum stress. c-Jun N-terminal kinases (JNK) are activated by inflammatory cytokines and have a key role in beta-cell apoptosis and in negative regulation of insulin signaling. JNK1-deficient mice are protected from diet-induced obesity and insulin resistance, while genetically obese mice with targeted mutations in JNK1 are leaner and have reduced insulin and blood glucose levels. These studies validate JNK as a link between inflammation and metabolic diseases and as a promising drug target. This review highlights recent advances in small-molecule inhibitors of JNK that have also been targeted for other diseases with an inflammatory component such as stroke, rheumatoid arthritis, and Alzheimer's and Parkinson's diseases.

Animals↗

Inflammatory pathways in atherosclerosis and acute coronary syndromes.

Evidence from a broad range of studies demonstrates that atherosclerosis is a chronic disease that, from its origins to its ultimate complications, involves inflammatory cells (T cells, monocytes, macrophages), inflammatory proteins (cytokines, chemokines), and inflammatory responses from vascular cells (endothelial cell expression of adhesion molecules). Investigators have identified a variety of proteins whose levels might predict cardiovascular risk. Of these candidates, C-reactive protein, tumor necrosis factor-alpha, and interleukin-6 have been most widely studied. There is also the prospect of inflammation as a therapeutic target, with investigators currently debating to what extent the decrease in cardiovascular risk seen with statins, angiotensin-converting enzyme inhibitors, and peroxisome proliferator-activated receptor ligands derives from changes in inflammatory parameters. These advances in basic and clinical science have placed us on a threshold of a new era in cardiovascular medicine.

Angina, Unstable↗

Renal collecting duct epithelial cells react to pyelonephritis-associated Escherichia coli by activating distinct TLR4-dependent and -independent inflammatory pathways.

TLR4 plays a central role in resistance to pyelonephritis caused by uropathogenic Escherichia coli (UPEC). It has been suggested that renal tubule epithelial cells expressing TLRs may play a key role in inflammatory disorders and in initiating host defenses. In this study we used an experimental mouse model of ascending urinary tract infection to show that UPEC isolates preferentially adhered to the apical surface of medullary collecting duct (MCD) intercalated cells. UPEC-infected C3H/HeJ (Lps(d)) mice carrying an inactivating mutation of tlr4 failed to clear renal bacteria and exhibited a dramatic slump in proinflammatory mediators as compared with infected wild-type C3H/HeOuJ (Lps(n)) mice. However, the level of expression of the leukocyte chemoattractants MIP-2 and TNF-alpha still remained greater in UPEC-infected than in naive C3H/HeJ (Lps(d)) mice. Using primary cultures of microdissected Lps(n) MCDs that expressed TLR4 and its accessory molecules MD2, MyD88, and CD14, we also show that UPECs stimulated both a TLR4-mediated, MyD88-dependent, TIR domain-containing adaptor-inducing IFN-beta-independent pathway and a TLR4-independent pathway, leading to bipolarized secretion of MIP-2. Stimulation by UPECs of the TLR4-mediated pathway in Lps(n) MCDs leads to the activation of NF-kappaB, and MAPK p38, ERK1/2, and JNK. In addition, UPECs stimulated TLR4-independent signaling by activating a TNF receptor-associated factor 2-apoptosis signal-regulatory kinase 1-JNK pathway. These findings demonstrate that epithelial collecting duct cells are actively involved in the initiation of an immune response via several distinct signaling pathways and suggest that intercalated cells play an active role in the recognition of UPECs colonizing the kidneys.

Animals↗

Role of inflammatory pathways in the development and cardiovascular complications of type 2 diabetes.

Experimental and epidemiologic studies support the role of inflammation in the development of type 2 diabetes and atherosclerosis. Serum levels of inflammatory markers, in particular highly sensitive C-reactive protein, have been found to be strong predictors of increased risk for type 2 diabetes and cardiovascular disease independent of traditional risk factors. A beneficial effect of thiazolidinediones, angiotensin-converting enzyme inhibitors, and statins in the prevention of type 2 diabetes and cardiovascular events has recently been reported, and potential anti-inflammatory mechanisms of action for these compounds have been described. Prospective, randomized clinical trials are currently underway to confirm these initial findings and define indications for treatment of patients at risk.

Cardiovascular Diseases↗

Cytokines and inflammatory pathways in the pathogenesis of multiple organ failure following abdominal aortic aneurysm repair.

Multiple organ failure is a common mode of death following abdominal aortic aneurysm repair, particularly after rupture. Cytokines are the principal mediators of the inflammatory response to injury and high levels of circulating cytokines have been associated with poor outcome in major trauma and sepsis. Abdominal aortic aneurysm repair results in an ischaemia-reperfusion injury to the tissues distal to the site of aortic clamping. The inflammatory response in these tissues causes the release of cytokines, principally Interleukins 1-beta, 6, and 8, and Tumour Necrosis Factor alpha. If released in large enough concentrations, these cytokines may enter the circulation and gain access to organs distant to the site of initial injury. Circulating cytokines cause dysfunction of the renal, cardiovascular, respiratory, nervous and musculo-skeletal systems. The combination of these individual changes in organ function is the multiple-organ dysfunction syndrome, which may progress to multiple organ failure.

Aortic Aneurysm, Abdominal↗

Inflammatory pathways between placenta and foetus.

Recent evidence indicates that intra-amniotic endotoxin (LPS) and interleukin-1 alpha (IL-1alpha) accelerate foetal lung maturity and protect from respiratory distress syndrome (RDS) more effectively than does antenatal glucocorticoid. Inflammatory cytokines promote development of chronic lung disease in the premature, acute RDS (ARDS) in children and adults. Systemic exposure to LPS or cytokines can result in generalized multiorgan damage. The abnormal host defence in the foetus and the premature newborn need to be considered in therapeutic interventions.

Cytokines↗

Complement: an inflammatory pathway fulfilling multiple roles at the interface of innate immunity and development.

Complement has been long perceived as an innate immune system that plays a pivotal role in the maintenance of host defense against infectious agents and the propagation of pro-inflammatory responses in the context of human disease. Complement activation has been associated with the onset of acute inflammatory reactions leading to complications such as acute graft rejection, local tissue injury and multi-organ failure. However, recent studies have indicated that various complement activation products may exert a beneficial effect by contributing to critical developmental and regenerative processes. Appreciating this extraordinary 'versatility' of complement proteins provides a framework for revisiting the design of effective complement therapeutics. A balanced strategy will have to consider limiting the detrimental proinflammatory effects of complement while preserving those activities that promote tissue repair and regeneration, cell survival and early development.

Animals↗

T-cell mediated inflammatory pathway in osteoarthritis.

Osteoarthritis (OA) is not caused by a simple consequence of aging and cartilage degradation. Based on the conventional paradigm, OA has been considered a degenerative joint disorder. However, the dominant clinical symptom has been characterized by a non-infectious chronic inflammatory condition with infiltration of inflammatory cells in the synovial tissue or synovial fluid, especially in the early stage of the disease. The inflammatory process appeared to develop degeneration of chondrocytes and/or formation of osteophytes. Immunohistochemical staining of synovial tissue with OA in the early stage, suggests the presence of T-cell infiltration in the perivascular area, some of which were CD4 positive T cells. Among the T cells, we identified the clonality of restricted TCR usage of Vbeta chain by single strand conformation polymorphism (SSCP) method on T-cell repertoire. Therefore we address the immune response in primary OA.

Humans↗

Host persistence: exploitation of anti-inflammatory pathways by Toxoplasma gondii.

Hosts that are infected with Toxoplasma gondii must mount a powerful immune response to contain dissemination of the parasite and to prevent mortality. After parasite proliferation has been contained by interferon-gamma-dependent responses, the onset of the chronic phase of infection is characterized by continuous cell-mediated immunity. Such potent responses are kept under tight control by a class of anti-inflammatory eicosanoid, the lipoxins. Here, we review such immune-containment strategies from the perspective of the host, which attempts to keep pro-inflammatory responses under control during chronic disease, as well as from the perspective of the pathogen, which hijacks the lipoxygenase machinery of the host for its own advantage, probably as an immune-escape mechanism.

Animals↗

Familial Mediterranean fever in the post-genomic era: how an ancient disease is providing new insights into inflammatory pathways.

Familial Mediterranean fever (FMF, MIM24900), described as a clinical entity only slightly over a half-century ago, has ancient roots among populations surrounding the Mediterranean basin. It is the most prevalent of the hereditary periodic fever syndromes, a group of disorders characterized by episodic attacks of fever and inflammation. Seven years ago, it was discovered that FMF is caused by mutations in MEFV, a gene that encodes a protein variously called pyrin or marenostrin. As exciting as that discovery was, physicians and patients alike were disappointed that the protein sequence of pyrin/marenostrin did not immediately suggest clues as to the molecular etiology of FMF. Though we are still far from a complete understanding of the function of pyrin/marenostrin at the cellular level, continued study of this intriguing protein is revealing new molecular details about inflammatory processes; the emerging information is relevant not only to FMF, but to innate immunity in general. Data from several laboratories demonstrate that pyrin/marenostrin is intimately connected to three important cellular pathways: apoptosis, cytoskeletal signaling and cytokine secretion. These connections occur, at least in part, through the direct interaction of the pyrin/marenostrin protein with two cytosolic protein adaptors: ASC (also called PyCARD or Tms1) and PSTPIP (also called CD2BP1). Here, we review the more recent literature regarding the molecular and cellular biology of pyrin/marenostrin and pinpoint open questions for future study.

Cytokines↗

HIV-Tat protein induces oxidative and inflammatory pathways in brain endothelium.

Impaired function of the brain vasculature might contribute to the development of HIV-associated dementia. For example, injury or dysfunction of brain microvascular endothelial cells (BMEC) can lead to the breakdown of the blood-brain barrier (BBB) and thus allow accelerated entry of the HIV-1 virus into the CNS. Mechanisms of injury to BMEC during HIV-1 infection are not fully understood, but the viral gene product Tat may be, at least in part, responsible for this effect. Tat can be released from infected perivascular macrophages in the CNS of patients with AIDS, and thus BMEC can be directly exposed to high concentrations of this protein. To study oxidative and inflammatory mechanisms associated with Tat-induced toxicity, BMEC were exposed to increasing doses of Tat1-72, and markers of oxidative stress, as well as redox-responsive transcription factors such as nuclear factor-kappaB (NF-kappaB) and activator protein-1 (AP-1), were measured. Tat1-72 treatment markedly increased cellular oxidative stress, decreased levels of intracellular glutathione and activated DNA binding activity and transactivation of NF-kappaB and AP-1. To determine if Tat1-72 can stimulate inflammatory responses in brain endothelium in vivo, expression of monocyte chemoattractant protein-1 (MCP-1), an NF-kappaB and AP-1-dependent chemokine, was studied in brain tissue in mice injected with Tat1-72 into the right hippocampus. Tat1-72 markedly elevated the MCP-1 mRNA levels in brain tissue. In addition, a double immunohistochemistry study revealed that MCP-1 protein was markedly overexpressed on brain vascular endothelium. These data indicate that Tat1-72 can induce redox-related inflammatory responses both in in vitro and in vivo environments. These changes can directly lead to disruption of the BBB. Thus, Tat can play an important role in the development of detrimental vascular changes in the brains of HIV-infected patients.

Animals↗

Maternal obesity is associated with dysregulation of metabolic, vascular, and inflammatory pathways.

Obesity is increasing in prevalence worldwide and in all age groups. In nonpregnant individuals, obesity is associated with dyslipidemia; hyperinsulinemia; vascular dysfunction; and, more recently, low-grade chronic inflammation. However, whether such effects are sustained during pregnancy has been sparsely investigated but is important to establish, given the association of maternal obesity with numerous adverse metabolic and vascular consequences. We consecutively recruited 47 healthy women in the third trimester of pregnancy and divided the participants into 2 groups, lean [n = 24; median body mass index (BMI), 22.1 kg/m(2)] and obese (n = 23; median BMI, 31.0 kg/m(2)) around the median first trimester BMI. The age, parity, and smoking history were comparable in both groups. A detailed panel of metabolic and inflammatory parameters was measured and an in vivo assessment of endothelial-dependent and -independent microvascular function made using laser doppler imaging. Although low-density lipoprotein cholesterol and glycosylated hemoglobin were similar, fasting triglyceride concentrations were higher [2.70 (interquartile range, 2.3-3.21) vs. 2.20 (IQ range, 2.0-2.6) mmol/liter, P = 0.02] and high-density lipoprotein concentrations were lower [1.55 (IQ range, 1.1-1.7) vs. 1.72 (IQ range, 1.4-2.0) mmol/liter, P = 0.02] in the obese group. Leptin [55.6 (range, 45-64.4) ng/ml vs. 23.8 (range, 13.2-35.2) ng/ml, P < 0.0001] and fasting insulin [14.5 (range, 11.4-27.3) vs. 6.5 (range, 4.6-9.7) mU/liter, P < 0.0001] levels were more than double. Similarly, levels of inflammatory parameters, IL-6 [3.15 (range, 2.4-3.5) vs. 2.1 (range, 1.73-2.85) pg/ml, P = 0.003], and sensitive C-reactive protein [4.45 (range, 2.9-6.6) vs. 2.25 (range, 0.92-3.65) mg/ml, P = 0.0015] were also substantially elevated. Both endothelial-dependent and -independent vasodilatory responses were significantly reduced in the obese group (P = 0.0003 and P = 0.02, respectively, ANOVA) and systolic blood pressure was higher (P = 0.01). Metabolic factors, C-reactive protein (r = 0.289, P = 0.049), and insulin (r = 0.339, P = 0.02) were related inversely to endothelial-dependent function. These comprehensive data demonstrate that, as in nonpregnant obese individuals, obesity in pregnancy is associated not only with marked hyperinsulinemia (without necessarily glucose dysregulation) and dyslipidemia but also impaired endothelial function, higher blood pressure, and inflammatory up-regulation. Such a spectrum of risk factors may contribute to maternal complications in obese women and, as a result, influence fetal programming of adult vascular disease. Clearly, these data provide further rationale to examine the potential benefits of preconceptual weight loss and antenatal exercise.

Adult↗