Tumor necrosis factor alpha, citrullination, and peptidylarginine deiminase 4 in lung and joint inflammation

BACKGROUND: The relationship between lung and joint inflammation in rheumatoid arthritis is poorly understood. Lung inflammation with resultant protein citrullination may trigger anti-citrullinated protein antibodies, inflammation, and arthritis. Alternatively, lung and joint inflammation may be two manifestations of a single underlying pathology. The lung has increased citrullination and TNF-alpha levels are high in rheumatoid arthritis; however, it is unknown if TNF-alpha can induce lung protein citrullination. The citrullinating enzyme peptidylarginine deiminase 4 (PAD4) exacerbates TNF-alpha-induced arthritis, but a role for PAD4 in lung citrullination and TNF-alpha-induced lung inflammation has not been explored. Our aim was to use TNF-alpha-overexpressing mice to clarify the intersection of TNF-alpha, citrullination, PAD4, arthritis, and lung inflammation. METHODS: Lung protein citrullination in wild-type mice, mice that overexpress TNF-alpha systemically (TNF(+)), TNF(+)PAD4(+/+), and TNF(+)PAD4(-/-) mice was quantified by both gel electrophoresis using a citrulline probe and western blot. Hematoxylin and eosin (HandE)-stained lung sections from TNF(+)PAD4(+/+) and TNF(+)PAD4(-/-) mice were scored for lung inflammation. HandE-stained ankle joint sections from mice that overexpress TNF-alpha only in the lungs were assessed for arthritis. RESULTS: TNF(+) mice have increased lung protein citrullination. TNF(+)PAD4(-/-) mice do not have significantly reduced lung protein citrullination, but do have decreased lung inflammation compared to TNF(+)PAD4(+/+) mice. Mice that overexpress TNF-alpha only in the lungs do not develop arthritis. CONCLUSIONS: PAD4 exacerbates lung inflammation downstream of TNF-alpha without having a major role in generalized protein citrullination in inflamed lungs. Also, TNF-alpha-induced lung inflammation is not sufficient to drive murine arthritis

Erratum: P53-regulated autophagy and its impact on drug resistance and cell fate

Wild-type p53 is a stress-responsive transcription factor and a potent tumor suppressor. P53 inhibits the growth of incipient cancer cells by blocking their proliferation or inducing their death through apoptosis. Autophagy is a self-eating process that plays a key role in response to stress. During autophagy, organelles and other intracellular components are degraded in autophagolysosomes and the autophagic breakdown products are recycled into metabolic and energy producing pathways needed for survival. P53 can promote or inhibit autophagy depending on its subcellular localization, mutation status, and the level of stress. Blocking autophagy has been reported in several studies to increase p53-mediated apoptosis, revealing that autophagy can influence cell-fate in response to activated p53 and is a potential target to increase p53-dependent tumor suppression

Insight into Neutrophil Extracellular Traps through Systematic Evaluation of Citrullination and Peptidylarginine Deiminases

In rheumatoid arthritis, an autoimmune inflammatory arthritis, citrullinated proteins are targeted by autoantibodies and thus thought to drive disease. Neutrophil extracellular traps (NETs) are a source of citrullinated proteins and are increased in rheumatoid arthritis and therefore also implicated in disease pathogenesis. However, not all NETs are citrullinated. One theory aiming to clarify the intersection of citrullination, NETs, and rheumatoid arthritis suggests that specific stimuli induce different types of NETs defined by citrullination status. However, most studies do not evaluate uncitrullinated NETs, only citrullinated or total NETs. Further, the requirement for peptidylarginine deiminase (PAD) 2 and 4, two important citrullinating enzymes in neutrophils and rheumatoid arthritis, in the formation of different NETs has not been clearly defined. To determine if specific stimulants induce citrullinated or uncitrullinated NETs and if those structures require PAD2 or PAD4, human and murine neutrophils, including from PAD4-/- and PAD2-/- mice, were stimulated in vitro and NETs imaged and quantified. In humans, phorbol myristate acetate (PMA), ionomycin, monosodium urate (MSU), and Candida albicans induced NETs with MSU and C. albicans inducing primarily citrullinated, PMA primarily uncitrullinated, and ionomycin a mix of NETs. Only ionomycin and C. albicans were strong inducers of NETs in mice with ionomycin-induced NETs mostly citrullinated and C. albicans-induced NETs a mix of citrullinated and uncitrullinated. Interestingly, no stimulus induced exclusively citrullinated or uncitrullinated NETs. Further, PAD4 was required for citrullinated NETs only, whereas PAD2 was not required for either NET in mice. Therefore, specific stimuli induce varying proportions of both citrullinated and uncitrullinated NETs with different requirements for PAD4. These findings highlight the complexity of NET formation and the need to further define the mechanisms by which different NETs form and their implications for autoimmune disease

Bulk Concentration Dependence of Electrolyte Resistance Within Mesopores of Carbon Electrodes in Electric Double-Layer Capacitors

Hexagonally ordered mesoporous carbon materials were prepared and used as electrode materials in an electric double-layer capacitor. Using this electrode, the change of electrolyte resistance within the mesopores was investigated according to the bulk electrolyte concentration. Using three different electrochemical transient experiments—imaginary capacitance analysis, chronoamperometry, and chronopotentiometry—the time constant associated with electrolyte transport was determined, which was then used to obtain the electrolyte resistance within the mesopores. With decreasing electrolyte concentration, the increase in electrolyte resistance was smaller than the increase in the resistivity of the bulk electrolyte, which is indicative of a different environment for ionic transport within the mesopores. On using the confinement effect within the mesopores, the predicted higher concentration within mesopore probably results in lower electrolyte resistance, especially under low bulk concentrations.1111Nsciescopuskc

The ethanolic extract of Aralia continentalis ameliorates cognitive deficits via modifications of BDNF expression and anti-inflammatory effects in a rat model of post-traumatic stress disorder

Abstract Background Post-traumatic stress disorder (PTSD) is a disease associated with that the experience of traumatic stress. The traumatic experience results in the development of a prolonged stress response that causes impaired memory function and increased inflammation in the hippocampus. Currently, antidepressants are the only approved therapy for PTSD. However, the efficacy of antidepressants in the treatment of PTSD is marginal. The ethanol extract of Aralia continentalis (AC) is traditionally used in oriental medicine, and has been showed to possess pharmacological properties, including anti-inflammatory, anti-cancer, anti-atherosclerotic, and anti-diabetic effects. Nevertheless, the effects of AC on cognitive memory and its mechanism of action in PTSD remain unclear. Given the necessity of further treatment options for PTSD, we investigated the effect of AC on the spatial cognitive impairment caused by single prolonged stress (SPS) in a rat model of PTSD. Methods Male rats were treated with various intraperitoneal (i.p.) doses of AC for 21 consecutive days after inducing chronic stress with the SPS procedure. Results Cognitive impairment caused by SPS were inhibited after treatment with 100 mg/kg AC, as measured by the Morris water maze test and an object recognition test. Additionally, AC treatment significantly alleviated memory-related decreases in brain-derived neurotrophic factor (BDNF) mRNA and protein levels in the hippocampus. Our results suggest that AC significantly inhibited the cognitive deficits caused by SPS via increased expression of pro-inflammatory cytokines, including tumor necrosis factor-α and interleukin-6, in the rat brain. Conclusions AC reversed the behavioral impairments and inflammation triggered by SPS-derived traumatic stress and should be further evaluated as a potential therapeutic drug for PTSD

Additional file 1: of DNA Area and NETosis Analysis (DANA): a High-Throughput Method to Quantify Neutrophil Extracellular Traps in Fluorescent Microscope Images

Figure S1. Immunofluorescent staining of DNA and myeloperoxidase (MPO) in neutrophils. (JPEG 3214 kb

Additional file 1: Figure S1. of Tumor necrosis factor alpha, citrullination, and peptidylarginine deiminase 4 in lung and joint inflammation

Increased Rh-PG and F95 binding to citrullinated fibronectin. Fibronectin purified from human blood was citrullinated in vitro as previously described [27]. Native (FN) and citrullinated (cit-FN) fibronectin were exposed to Rh-PG followed by gel electrophoresis, imaging of Rh-PG, and staining with brilliant blue to detect total protein. a Representative gels. b Average and SEM are graphed for total Rh-PG signal normalized to total protein. FN and cit-FN were subjected to western blot using the F95 antibody and gel electrophoresis with brilliant blue to detect total protein. c Representative blot (upper) and gel (lower). d Average and SEM are graphed for total F95 signal normalized to total protein. For all panels, n = 3 experiments, ** p < 0.01, *** p < 0.001. (PDF 1349 kb

Additional file 1: of DNA Area and NETosis Analysis (DANA): a High-Throughput Method to Quantify Neutrophil Extracellular Traps in Fluorescent Microscope Images

Figure S1. Immunofluorescent staining of DNA and myeloperoxidase (MPO) in neutrophils. (JPEG 3214 kb

Additional file 2: of DNA Area and NETosis Analysis (DANA): a High-Throughput Method to Quantify Neutrophil Extracellular Traps in Fluorescent Microscope Images

Figure S2. Marker analysis of NET-like structures. (PDF 967 kb