Interleukin-8 (IL-8) is a chemotactic factor for T-lymphocytes and smooth muscle cells and may therefore have an important effect in atherogenesis. It is secreted from oxysterol-containing foam cells which have been found in hypoxic zones in atherosclerotic plaques. The aim of this study was to investigate the effect of hypoxia on the secretion of IL-8 by oxysterol-stimulated macrophages. Hypoxia enhances 25-hydroxycholesterol (25-OH-chol)-induced IL-8 secretion in human monocyte-derived macrophages. The effect is most pronounced when macrophages are incubated with low concentrations of 25-OH-chol. Both 25-OH-chol and hypoxia increases the intracellular level of the signalling molecule hydrogen peroxide (H(2)O(2)). This event coincided with an enhanced binding of the transcription factor c-jun to the IL-8 gene promoter and an increased IL-8 mRNA expression in hypoxic macrophages. These observations suggest that similar intracellular signalling pathways are used for both 25-OH-chol-induced IL-8 expression and hypoxia-induced IL-8 expression. Thus, hypoxia in atherosclerotic plaques may increase the secretion of IL-8 from oxysterol-containing foam cells, which subsequently may accelerate the progression of atherosclerosis.
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http://dx.doi.org/10.1016/s0021-9150(03)00302-2 | DOI Listing |
J Clin Invest
January 2025
Department of Medicine, University of California San Francisco, San Francisco, United States of America.
Hypoxia is a major cause of pulmonary hypertension (PH) worldwide, and it is likely that interstitial pulmonary macrophages contribute to this vascular pathology. We observed in hypoxia-exposed mice an increase in resident interstitial macrophages, which expanded through proliferation and expressed the monocyte recruitment ligand CCL2. We also observed an increase in CCR2+ macrophages through recruitment, which express the protein thrombospondin-1 that functionally activates TGF-beta to cause vascular disease.
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Physical Activity, Sport and Exercise (PHASE) Research Group, School of Allied Health (Exercise Science), Murdoch University, Perth, Australia.
This study examined internal, external training loads, internal:external ratios, and aerobic adaptations for acute and short-term chronic repeated-sprint training (RST) with blood flow restriction (BFR). Using randomised crossover (Experiment A) and between-subject (Experiment B) designs, 15 and 24 semi-professional Australian footballers completed two and nine RST sessions, respectively. Sessions comprised three sets of 5-7 × 5-second sprints and 25 seconds recovery, with continuous BFR (45% arterial occlusion pressure) or without (Non-BFR).
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October 2023
Institute of Medical Plant Physiology and Ecology, School of Pharmaceutical Sciences, Guangzhou University of Chinese Medicine, Guangzhou, 510006, China.
Optimizing central carbon metabolism (CCM) represents an attractive and challenging strategy to improve the biosynthesis of valuable chemicals due to the complex regulation of the CCM in yeast. In this study, we triggered the similar Warburg effect of cancer cells in yeast strains by introducing the human hypoxia-inducible factor-1 (HIF-1) complex, which regulated the expression of numerous enzymes involved in CCM and redirected the metabolic flux from glycolysis to tricarboxylic acid cycle. This redirection promoted the production of squalene to a 2.
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Department of Biology, Adelphi University, One South Avenue, P.O. Box 701, Garden City, NY, 11530-0701, USA.
Background: von Hippel-Lindau (VHL) hereditary cancer syndrome is caused by mutations in the VHL tumor suppressor gene and is characterized by a predisposition to form various types of tumors, including renal cell carcinomas, hemangioblastomas, and pheochromocytomas. The protein products of the VHL gene, pVHL, are part of an ubiquitin ligase complex that tags hypoxia inducible factor alpha (HIF-α) for proteosomal degradation. pVHL has also been reported to bind to atypical protein kinase C (aPKC).
View Article and Find Full Text PDFJ Exp Biol
January 2025
Department of Ocean Sciences, Memorial University of Newfoundland and Labrador, St. John's, NL. A1C 5S7, Canada.
With climate change, fish are facing rising temperatures, an increase in the frequency and severity of heat waves and hypoxia, sometimes concurrently. However, only limited studies have examined the combined effects of increases in temperature and hypoxia on fish physiology and survival. We measured the cardiorespiratory physiology of 12°C-acclimated Atlantic salmon when exposed acutely to normoxia [100% air saturation (sat.
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