Plos One
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Hypoxia-inducible factor 1 (HIF-1) is a master regulator of cellular adaptation to hypoxia and has been suggested as a potent therapeutic target in cerebral ischemia. Here we show in an ischemic stroke model of rats that inhibiting HIF-1 and its downstream genes by 3-(5'-hydroxymethyl-2'-furyl)-1-benzylindazole (YC-1) significantly increases mortality and enlarges infarct volume evaluated by MRI and histological staining. Interestingly, the HIF-1 inhibition remarkably ameliorates ischemia-induced blood-brain barrier (BBB) disruption determined by Evans blue leakage although it does not affect brain edema. ⋯ Further analyses show that ischemia upregulates HIF-1 and its downstream genes erythropoietin (EPO), vascular endothelial growth factor (VEGF), and glucose transporter (Glut) in neurons and brain endothelial cells and that YC-1 inhibits their expression. We postulate that HIF-1-induced VEGF increases BBB permeability while certain other proteins coded by HIF-1's downstream genes such as epo and glut provide neuroprotection in an ischemic brain. The results indicate that YC-1 lacks the potential as a cerebral ischemic treatment although it confers certain protection to the cerebral vascular system.
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The combination of sarcopenia, age-related loss of muscle strength and mass, and obesity has been recognized as a new category of obesity among the elderly. Given that leptin has been hypothesized to be involved in the pathogenesis of sarcopenic obesity, we investigated the relationship between plasma leptin levels and thigh muscle sarcopenia and visceral obesity. Thigh muscle cross-sectional area (CSA) and visceral fat area were measured using computed tomography as indices for muscle mass and visceral fat, respectively, in 782 middle-aged to elderly subjects (303 men and 479 women), participating in a medical check-up program. ⋯ Subjects were divided into four groups based on presence or absence of sarcopenia or visceral obesity. Plasma levels of leptin were higher in subjects with sarcopenic visceral obesity than in those with either sarcopenia or visceral obesity alone. These findings indicate that sarcopenic visceral obesity is a more advanced, and suggest that leptin may link visceral obesity and sarcopenia.
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Asthma is a chronic inflammatory airways disease in which respiratory viral infections frequently trigger exacerbations. Current treatment of asthma with combinations of inhaled corticosteroids and long acting beta2 agonists improves asthma control and reduces exacerbations but what impact this might have on innate anti-viral immunity is unclear. We investigated the in vitro effects of asthma drugs on innate anti-viral immunity. ⋯ Notably, RV16 stimulated lower levels of type Myxovirus A and oligoadenylate synthase in PBMC of asthmatics than control donors. These in vitro studies demonstrate that combinations of drugs commonly used in asthma therapy inhibit both early pro-inflammatory cytokines and key aspects of the type I IFN pathway. These findings suggest that budesonide and formoterol curtail excessive inflammation induced by rhinovirus infections in patients with asthma, but whether this inhibits viral clearance in vivo remains to be determined.
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Glial fibrillary acidic protein (GFAP) is a specific intermediate filament of the cytoskeleton of the astrocyte and may be used as a specific marker for astrocytic damage. It is detectable in the cerebrospinal fluid following a relapse caused by Multiple Sclerosis (MS) and Neuromyelitis Optica (NMO) spectrum disease. Higher levels are found following an NMO-related relapse. It is not known if GFAP is also detectable in the serum following such relapses. In particular, it is not known if lesions limited to the optic nerve release GFAP in sufficient quantities to be detectable within the serum. The aim of this study was to ascertain the extent to which serum GFAP levels can distinguish between an episode of optic neuritis (ON) related to NMO spectrum disease and ON from other causes. ⋯ Glial pathology in NMO related optic neuritis is reflected in elevated serum GFAP levels independently of whether or not there is extra-optic nerve disease.
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Mitochondrial potassium channels are important mediators of cell protection against stress. The mitochondrial large-conductance "big" K(+) channel (mBK) mediates the evolutionarily-conserved process of anesthetic preconditioning (APC), wherein exposure to volatile anesthetics initiates protection against ischemic injury. Despite the role of the mBK in cardioprotection, the molecular identity of the channel remains unknown. ⋯ Instead, we found that the related but physiologically-distinct K(+) channel SLO2 was required, and that SLO2-dependent mitochondrial K(+) transport was triggered directly by volatile anesthetics. In addition, a SLO2 channel activator mimicked the protective effects of volatile anesthetics. These findings suggest that SLO2 contributes to protection from hypoxic injury by increasing the permeability of the mitochondrial inner membrane to K(+).