Obesity-induced chronic inflammation in C57Bl6J mice, a novel risk factor in the progression of renal AA amyloidosis?

Background: Compelling evidence links obesity induced systemic inflammation to the development of chronic kidney disease (CKD). This systemic inflammation may result from exacerbated adipose inflammation. Besides the known detrimental effects of typical pro-inflammatory factors secreted by the adipose tissue (TNF-α, MCP-1 and IL-6) on the kidney, we hypothesize the enhanced obesity-induced secretion of serum amyloid A (SAA), an acute inflammatory protein, to play a key role in aggravating obesity-induced CKD. Methods: Groups of male C57Bl/6J mice (n = 99 in total) were fed a low (10% lard) or high (45% lard) fat diet for a maximum of 52 weeks. Mice were sacrificed after 24, 40 and 52 weeks. Whole blood samples, kidneys and adipose tissues were collected. The development of adipose and renal tissue inflammation was assessed on gene expression and protein level. Adipocytokine levels were measured in plasma samples. Results: A distinct inflammatory phenotype was observed in the adipose tissue of HFD mice prior to renal inflammation, which was associated with an early systemic elevation of TNF-α, leptin and SAA (1A-C). With aging, sclerotic lesions appeared in the kidney, the extent of which was severely aggravated by HFD feeding. Lesions exhibited typical amyloid characteristics (2A) and pathological severity positively correlated with bodyweight (2B). Interestingly, more SAA protein was detected in lesions of HFD mice. Conclusion: Our data suggest a causal link between obesity induced chronic inflammation and AA amyloidosis in C57Bl/6J mice. Though future studies are necessary to prove this causal link and to determine its relevance for the human situation, obesity may hence be considered a risk factor for the development and progression of renal AA amyloidosis in the course of CKD. (Figure Presented)

Diagnostic performance of transthyretin measurement in fat tissue of patients with ATTR amyloidosis

In this article, the diagnostic performance of a transthyretin (TTR) ELISA for detection and characterization of transthyretin-derived (ATTR) amyloid in abdominal subcutaneous fat tissue was studied. Fat tissue specimens were analyzed of 38 patients with ATTR amyloidosis, 70 controls, and 17 carriers of a TTR mutation. Amyloid amount was graded semi-quantitatively in Congo red-stained specimens (0-4+). Amyloid was extracted from tissue in guanidine, and the TTR concentration was measured using a sandwich TTR-ELISA. The TTR concentration of patients with ATTR amyloidosis (mean 0.84 ng/mg fat tissue) was significantly higher than controls (p<0.001). With a TTR concentration of 0.13 ng/mg fat tissue as cut-off value, 32 of the 38 ATTR patients were identified resulting in a sensitivity of 84%. Sixty-seven of the 70 controls had values below the cut-off value resulting in a specificity of 96%. Thus, measuring TTR in fat tissue is useful for detecting ATTR amyloidosis and for characterizing amyloid as ATTR type

A pair of peptides inhibits seeding of the hormone transporter transthyretin into amyloid fibrils

The tetrameric protein transthyretin is a transporter of retinol and thyroxine in blood, cerebrospinal fluid, and the eye, and is secreted by the liver, choroid plexus, and retinal epithelium, respectively. Systemic amyloid deposition of aggregated transthyretin causes hereditary and sporadic amyloidoses. A common treatment of patients with hereditary transthyretin amyloidosis is liver transplantation. However, this procedure, which replaces the patient's variant transthyretin with the WT protein, can fail to stop subsequent cardiac deposition, ultimately requiring heart transplantation. We recently showed that preformed amyloid fibrils present in the heart at the time of surgery can template or seed further amyloid aggregation of native transthyretin. Here we assess possible interventions to halt this seeding, using biochemical and EM assays. We found that chemical or mutational stabilization of the transthyretin tetramer does not hinder amyloid seeding. In contrast, binding of the peptide inhibitor TabFH2 to ex vivo fibrils efficiently inhibits amyloid seeding by impeding self-association of the amyloid-driving strands F and H in a tissue-independent manner. Our findings point to inhibition of amyloid seeding by peptide inhibitors as a potential therapeutic approach.This work was supported by Amyloidosis Foundation Grant 20160759 and 20170827, National Institutes of Health Grant R01-AG048120, and The Howard Hughes Medical Institute. The authors and UCLA have filed an international patent application for the TTR inhibitors (number PCT/US17/40103). D. S. E. is an advisor and equity holder of ADRx, Inc. L. S. is a consultant of ADRx, Inc. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.info:eu-repo/semantics/publishedVersio

Small artery elasticity is decreased in patients with systemic lupus erythematosus without increased intima media thickness

Introduction: The objectives of this study were to determine small arterial elasticity (SAE) in systemic lupus erythematosus (SLE) and to investigate its relationship with intima media thickness (IMT), accumulation of advanced glycation end products (AGEs), endothelial activation and inflammation. Methods: Thirty SLE patients with inactive disease and 30 age- and sex-matched healthy controls were included. Twenty patients with essential hypertension (EH) served as positive control. SAE was assessed by pulse-wave analysis using tonometric recordings of the radial artery. IMT of the carotid arteries was measured by ultrasound. AGE accumulation was assessed with an AGE-reader. Endothelial activation markers and C-reactive protein (CRP) were determined by enzyme-linked immunosorbent assay (ELISA). Results: SAE was decreased in SLE (P = 0.01) and further decreased in EH (P <0.01) compared to healthy controls. IMT was increased in EH (P <0.05), but not in SLE. AGE accumulation was increased in SLE (P <0.05) and further increased in EH (P <0.01) compared to healthy controls. Endothelial activation markers and CRP were increased in SLE but not in EH. SAE related to AGE accumulation (r = -0.370, P <0.05), CRP (r = -0.429, P <0.05) and creatinine clearance (r = 0.440, P <0.05), but not to IMT and endothelial activation markers. In multivariate analysis SLE was an independent predictor of SAE. Conclusions: SAE is decreased in SLE patients without increased IMT, independently of traditional cardiovascular risk factors. Longitudinal studies are needed to investigate whether SAE, endothelial activation and AGE accumulation are early markers for cardiovascular disease in SLE

Late onset cardiomyopathy as presenting sign of ATTR A45G amyloidosis caused by a novel TTR mutation (p.A65G)

Objective: The clinical description of a novel TTR genemutation characterized by a late onset amyloid cardiomyopathy.Methods and Results: A 78-year-old man of Dutch origin with recent surgeryforbilateral carpal tunnel syndrome(CTS) was admitted to our hospital because of heart failure with preserved ejection fraction (55%). Cardiac ultrasound showed thickened biventricular walls, and cardiac magnetic resonance imaging also showed late gadolinium enhancement. Early signs of a polyneuropathy were found by neurophysiological testing. A few months later, his 72year- old sister was admitted to an affiliated hospital because of heart failure caused by a restrictive cardiomyopathy. In both patients, a subcutaneous abdominal fat aspirate was stained with Congo red and DNA was analyzed by direct sequencing of exons 1 to 4 of the transthyretin (TTR) gene. Both fat aspirates revealed transthyretin-derived (ATTR) amyloid. Tc-99m-diphosphonate scintigraphy further confirmed cardiac ATTR amyloidosis in the male patient. DNA analysis of both patients showed a novel TTR mutation c.194C&gt;G that encodes for the gene product TTR (p.A65G) ending up as themature protein TTR A45G. The 56-year-old daughter of themale patient had the same TTR mutation. A full diagnostic workup did not reveal any signs of amyloidosis yet.Conclusions: A novel amyloidogenic TTRmutation was found in a Dutch family. The clinical presentation of ATTR A45G amyloidosis in the affected family members was heart failure due to a late-onset cardiomyopathy. The systemic nature of this disease was reflected by bilateral CTS and by early signs of a polyneuropathy in the index patient.</p

Plasma Pyruvate Kinase M2 as a marker of vascular inflammation in Giant Cell Arteritis

OBJECTIVES: Giant Cell Arteritis (GCA) is a large vessel vasculitis in which metabolically active immune cells play an important role. GCA diagnosis is based on CRP/ESR and temporal artery biopsies (TABs), in combination with [18F]FDG-PET/CT relying on enhanced glucose uptake by glycolytic macrophages. Here, we studied circulating Pyruvate Kinase M2 (PKM2), a glycolytic enzyme, as a possible systemic marker of vessel wall inflammation in GCA. METHODS: Immunohistochemical detection of PKM2 was performed on inflamed (n = 12) and non-inflamed (n = 4) TABs from GCA patients and non-GCA (n = 9) patients. Dimeric PKM2 levels were assessed in plasma of GCA patients (n = 44), age-matched healthy controls (HC, n = 41), metastatic melanoma patients (n = 7) and infection controls (n = 11). CRP, ESR and macrophage markers calprotectin and YKL-40 were correlated with plasma PKM2 levels. To detect the cellular source of plasma PKM2 in tissue, double immunofluorescence staining was performed on inflamed GCA TABs. [18F]FDG-PET scans of 23 GCA patients were analyzed and maximum standard uptake values (SUVmax) and target to background ratios (TBR) were calculated. RESULTS: PKM2 is abundantly expressed in TABs of GCA patients. Dimeric PKM2 plasma levels were elevated in GCA and correlated with CRP, ESR, calprotectin, and YKL-40 levels. Elevated plasma PKM2 levels were downmodulated by GC-treatment. PKM2 was detected in both macrophages and T cells at the site of vascular inflammation. Circulating PKM2 levels correlated with average TBR PET scores. CONCLUSION: Elevated plasma PKM2 levels reflect active vessel inflammation in GCA and may assist in disease diagnosis and in disease monitoring

Особливості синтаксичної організації художньої прози Редьярда Кіплінга

Статья посвящена исследованию синтаксических конструкций, с помощью которых в художественной прозе Редьярда Киплинга отображаются особенности английской и индийской культур.Стаття присвячена дослідженню синтаксичних конструкцій, за допомогою яких у художній прозі Редьярда Кіплінга відображено особливості англійської та індійської культур.The article is dedicated to the investigation of the main syntactic constractions with the help of which in the prose of Rudyard Kipling there are depicted the peculiarities of English and Indian cultures