Probes for IL6

Neovascular age-related macular degeneration (nAMD) commonly causes vision loss from aberrant angiogenesis, termed choroidal neovascularization (CNV). Interleukin-6 (IL6) is a pro-inflammatory and pro-angiogenic cytokine that is correlated with AMD progression and nAMD activity. We hypothesize that anti-IL6 therapy is a potential nAMD therapeutic. We found that IL6 levels were increased after laser injury and expressed by macrophages. Il6-deficiency decreased laser-induced CNV area and exogenous IL6 addition increased choroidal sprouting angiogenesis. Il6-null mice demonstrated equally increased macrophage numbers as wildtype mice. At steady state, IL6R expression was detected on peripheral blood and ocular monocytes. After laser injury, the number of IL6R+Ly6C+ monocytes in blood and IL6R+ macrophages in the eye were increased. In human choroid, macrophages expressed IL6, IL6R, and IL6ST. Furthermore, IL6R+ macrophages displayed a transcriptional profile consistent with STAT3 (signal transducer and activator of transcription 3) activation and angiogenesis. Our data show that IL6 is both necessary and sufficient for choroidal angiogenesis. Macrophage-derived IL6 may stimulate choroidal angiogenesis via classical activation of IL6R+ macrophages, which then stimulate angiogenesis. Targeting IL6 or the IL6R could be an effective adjunctive therapy for treatment-resistant nAMD patients.

Used restaurant oil offers a sustainable and affordable energy source in broiler diets but variable lipid composition and the presence of harmful peroxidation products may alter intestinal immunity. The objective of this study was to evaluate the effects of feeding different lipid sources with variable peroxidation statuses on immune cell populations producing interleukin-6 (IL6) and interferon-γ (IFNG) in the broiler ileum. Two hundred broilers were fed diets with 5% inclusion of control or peroxidized palm, soybean, flaxseed or fish oil in a 4 × 2 factorial treatment design. At 21d, 2 birds/ treatment were euthanized for ileum collection and immune cell populations were analyzed by RNAscope- in situ hybridization (ISH). Ileal production of IL6 increased 85.8% by feeding peroxidized flaxseed oil while IFNG-producing cells were increased 55.1-59.9% by feeding either control or peroxidized soybean oil (P ≤ 0.05). Feeding peroxidized lipid generally reduced CD3+ T cells not producing either IL6 or IFNG by 14.9-39.0% (P ≤ 0.05). Overall, these results suggest that IL6 and IFNG have differential responses to lipid source and peroxidation while lipid peroxidation negatively impacts T cell presence in the broiler chicken ileum. Inflammatory outcomes observed in broilers fed peroxidized flaxseed oil suggest that yellow grease containing this type of oil may detrimentally impact broilers, while soybean oil generally contributes to intestinal inflammation regardless of heat exposure

Kynurenine 3-monooxygenase (KMO) regulates the levels of neuroactive metabolites in the kynurenine pathway (KP), dysregulation of which is associated with Huntington's disease (HD) pathogenesis. KMO inhibition leads to increased levels of neuroprotective relative to neurotoxic metabolites, and has been found to ameliorate disease-relevant phenotypes in several HD models. Here, we crossed KMO knockout mice to R6/2 HD mice to examine the effect of KMO depletion in the brain and periphery. KP genes were dysregulated in peripheral tissues from R6/2 mice and KMO ablation normalised levels of a subset of these. KP metabolites were also assessed, and KMO depletion led to increased levels of neuroprotective kynurenic acid in brain and periphery, and dramatically reduced neurotoxic 3-hydroxykunurenine levels in striatum and cortex. Notably, the increased levels of pro-inflammatory cytokines TNFa, IL1β, IL4 and IL6 found in R6/2 plasma were normalised upon KMO deletion. Despite these improvements in KP dysregulation and peripheral inflammation, KMO ablation had no effect upon several behavioural phenotypes. Therefore, although genetic inhibition of KMO in R6/2 mice modulates several metabolic and inflammatory parameters, these do not translate to improvements in primary disease indicators-observations which will likely be relevant for other interventions targeted at peripheral inflammation in HD.

Cardiac manifestations are common in severe COVID-19. This study compared the histologic, viral, and molecular findings in cardiac tissue in fatal COVID-19 (n = 11) and controls (n = 11). In situ hybridization (SARS-CoV2 RNA) and immunohistochemistry for viral proteins and the host response were quantified for the samples and compared with qRTPCR and Western blot data. Control hearts showed a high resident population of macrophages that had variable ACE2 expression. Cardiac ACE2 expression was 10× greater in the heart tissues of cases and controls with obesity or type II diabetes. Multifocal endothelial cell swelling and degeneration, perivascular edema plus microvascular thrombi were unique to the cases. SARS-CoV2 RNA and nucleocapsid protein were rarely detected in situ in any COVID-19 heart. However, in each case abundant SARS-CoV-2 spike protein was evident. Co-expression experiments showed that the spike protein localized mostly to the ACE2+ interstitial macrophages/pericytes that were activated as evidenced by increased IL6 and TNFα expression. Western blots confirmed the presence of the viral spike protein, but not the nucleocapsid protein, in the cardiac homogenates. The intercalated disc proteins connexin 43, the primary cardiac gap junction protein, and NaV1.5, the predominant cardiac sodium channel, each showed marked lateral migration in the myocytes in the cases, which would increase the risk of reentrant arrhythmias. It is concluded that the viral spike protein, endocytosed by macrophages/pericytes, can induce a myocarditis with the possibility of conduction dysfunction due to abnormal localization of key intercalated disc proteins.