224 research outputs found

    Enhanced osteogenesis of human urine-derived stem cells by direct delivery of 30Kc19α–Lin28A protein

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    Urine-derived stem cells (USCs) are a promising source for regenerative medicine because of their advantages such as easy and non-invasive collection from the human body, stable expansion, and the potential to differentiate into multiple lineages, including osteoblasts. In this study, we propose a strategy to enhance the osteogenic potential of human USCs using Lin28A, a transcription factor that inhibits let-7 miRNA processing. To address concerns regarding the safety of foreign gene integration and potential risk of tumorigenicity, we intracellularly delivered Lin28A as a recombinant protein fused with a cell-penetrating and protein-stabilizing protein, 30Kc19α. 30Kc19α–Lin28A fusion protein exhibited improved thermal stability and was delivered into USCs without significant cytotoxicity. 30Kc19α–Lin28A treatment elevated calcium deposition and upregulated several osteoblast-specific gene expressions in USCs derived from multiple donors. Our results indicate that intracellularly delivered 30Kc19α–Lin28A enhances the osteoblastic differentiation of human USCs by affecting the transcriptional regulatory network involved in metabolic reprogramming and stem cell potency. Therefore, 30Kc19α–Lin28A may provide a technical advancement toward developing clinically feasible strategies for bone regeneration

    Cerebral Venous Thrombosis and Livedo Reticularis in a Case with MTHFR 677TT Homozygote

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    Hyperhomocysteinemia associated with methylene terahydrofolate reductase (MTHFR) mutation can be a risk factor for idiopathic cerebral venous thrombosis. We describe the first case of MTHFR 677TT homozygote with cerebral venous thrombosis and livedo reticularis. A 45-year-old man presented with seizures and mottled-like skin lesions, that were aggravated by cold temperature. Hemorrhagic infarct in the right frontoparietal area with superior sagittal sinus thrombosis was observed. He had hyperhomocysteinemia, low plasma folate level, and MTHFR 677TT homozygote genotype, which might be associated with livedo reticularis and increase the risk for cerebral venous thrombosis

    Primary Diffuse Leptomeningeal Gliomatosis: Report of a Case Presenting with Chronic Meningitis

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    Neoplastic meningitis occurs in approximately 5% of patients with cancer. Primary diffuse leptomeningeal gliomatosis is a rare condition whereby a glioma arises from heterotopic cell nests in the leptomeninges. We report here a case presenting with clinical features similar to those of chronic infectious meningitis without positive cerebrospinal fluid cytology. Neurological signs in our patient deteriorated progressively without responding to antitubercular, antiviral, or antibiotic therapy. Leptomeningeal biopsy sampling revealed the condition to be primary diffuse leptomeningeal gliomatosis

    Migraine-like Headache in a Patient with Complement 1 Inhibitor Deficient Hereditary Angioedema

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    We report on an angioedema patient with a genetic defect in complement 1 inhibitor, manifesting migraine-like episodes of headache, effective prophylaxis with Danazol, and triptan for a treatment of acute clinical episode. The patient was 44-yr-old Korean man with abdominal pain and headache, who was brought into the Emergency Department of Seoul National University Hospital, Seoul. He suffered from frequent attacks of migraine-like headache (3-7 per month), pulsating in nature associated with nausea. Severities were aggravated by activity and his headache had shown recent progression with abdominal pain. No remarkable findings were observed on radiologic examination, brain magnetic resonance images and intracranial and extracranial magnetic resonance angiography. Danazol 200 mg every other day was subsequently used. Following administration of Danazol, symptoms showed improvement and the patient was discharged. While taking Danazol, the migraine-like episodes appeared to be prevented for about 2 yr. At the eighth month, he suffered a moderate degree of migraine-like headache; however, administration of naratriptan 2.5 mg resolved his problem. A case of genetic defect of C1-INH deficiency presented with headache episodes, and was controlled by Danazol and triptan. It suggests that pathogenic mechanism of headache in hereditary angioedema may be mediated by the neurogenic inflammatory-like physiology of migraine

    A Korean Case of Juvenile Muscular Atrophy of Distal Upper Extremity (Hirayama Disease) with Dynamic Cervical Cord Compression

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    We present a Korean case of Hirayama disease with its typical neuroradiological findings of forward displacement of cervical dural sac and compression of the lower cervical cord during neck flexion. A 15-yr-old boy was presented with a one-year history of progressive weakness and atrophy affecting bilateral hands and forearms. The electrodiagnostic findings were compatible with the lesion of the anterior horn cells at the C7, C8, and T1 spinal segments. With neck flexion, cervical magnetic resonance imaging (MRI) showed the anterior shifting of the lower cervical dural sac resulting in the cord compression of those segments. Presumably, this disease might have been prevalent in Korea frequently under the diagnosis of "benign focal amyotrophy". In this regard, we discuss the clinical importance of cervical MRI with neck flexion and anticipate the increasing reports of the case substantiated by its characteristic radiological features

    Cluster-like Headache Secondary to Cerebral Venous Thrombosis

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    Cluster headache (CH) is considered a primary headache syndrome. However, symptomatic cases that resemble CH have also been reported. A patient with cerebral venous thrombosis presented with ipsilateral frontal pain accompanied by ophthalmoparesis, nasal congestion, and lacrimation. The patient's headache showed a dramatic response to oxygen. He experienced no further cluster-like headaches after treatment with an anticoagulant. This case suggests the possible role of venous stasis of the cavernous sinus in cluster-like headache

    Dose-specific effect of simvastatin on hypoxia-induced HIF-1α and BACE expression in Alzheimers disease cybrid cells

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    This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited.Abstract Background Alzheimers disease (AD) is associated with vascular risk factors; brain ischemia facilitates the pathogenesis of AD. Recent studies have suggested that the reduction of AD risk with statin was achieved by decreased amyloidogenic amyloid precursor protein. Methods We used mitochondrial transgenic neuronal cell (cybrid) models to investigate changes in the levels of intracellular hypoxia inducible factor 1α (HIF-1α) and β-site amyloid precursor protein cleaving enzyme (BACE) in the presence of simvastatin. Sporadic AD (SAD) and age-matched control (CTL) cybrids were exposed to 2 % O2 and incubated with 1 μM or 10 μM simvastatin. Results There was no significant difference between cell survival by 1 or 10 μM simvastatin in both SAD and CTL cybrids. In the presence of 1 μM simvastatin, intracellular levels of HIF-1α and BACE decreased by 40–70 % in SAD, but not CTL cybrids. However, 10 μM simvastatin increased HIF-1α and BACE expression in both cybrid models. Conclusion Our results suggest demonstrate differential dose-dependent effects of simvastatin on HIF-1α and BACE in cultured Alzheimers disease cybrid cells

    Downregulated miR-18b-5p triggers apoptosis by inhibition of calcium signaling and neuronal cell differentiation in transgenic SOD1 (G93A) mice and SOD1 (G17S and G86S) ALS patients

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    Abstract Background MicroRNAs (miRNAs) are endogenous non-coding RNAs that regulate gene expression at the post-transcriptional level and are key modulators in neurodegenerative diseases. Overexpressed miRNAs play an important role in ALS; however, the pathogenic mechanisms of deregulated miRNAs are still unclear. Methods We aimed to assess the dysfunction of RNAs or miRNAs in fALS (SOD1 mutations). We compared the RNA-seq of subcellular fractions in NSC-34 WT (hSOD1) and MT (hSOD1 (G93A)) cells to find altered RNAs or miRNAs. We identified that Hif1α and Mef2c were upregulated, and Mctp1 and Rarb were downregulated in the cytoplasm of NSC-34 MT cells. Results SOD1 mutations decreased the level of miR-18b-5p. Induced Hif1α which is the target for miR-18b increased Mef2c expression as a transcription factor. Mef2c upregulated miR-206 as a transcription factor. Inhibition of Mctp1 and Rarb which are targets of miR-206 induces intracellular Ca2+ levels and reduces cell differentiation, respectively. We confirmed that miR-18b-5p pathway was also observed in G93A Tg, fALS (G86S) patient, and iPSC-derived motor neurons from fALS (G17S) patient. Conclusions Our data indicate that SOD1 mutation decreases miR-18b-5p, which sequentially regulates Hif1α, Mef2c, miR-206, Mctp1 and Rarb in fALS-linked SOD1 mutation. These results provide new insights into the downregulation of miR-18b-5p dependent pathogenic mechanisms of ALS

    Early intravenous infusion of sodium nitrite protects brain against in vivo ischemia-reperfusion injury

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    BACKGROUND AND PURPOSE: The rate of nitric oxide (NO) generation from nitrite is linearly dependent on reductions in oxygen and pH levels. Recently, nitrite-derived NO has been reported to exert a profound protection against liver and heart ischemia-reperfusion injury. In this study, we hypothesized that nitrite would be reduced to NO in the ischemic brain and exert NO-dependent neuroprotective effects. METHODS: Cerebral ischemia-reperfusion injury was induced by intraluminal thread occlusion of middle cerebral artery in the adult male rats. Solutions of sodium nitrite were infused intravenously at the time of reperfusion. Sodium nitrate and carboxy-PTIO (30 minutes before ischemic surgery), a direct NO scavenger, were infused for comparisons. RESULTS: Nitrite reduced infarction volume and enhanced local cerebral blood flow and functional recovery. The effects were observed at concentrations of 48 nmol and 480 nmol, but not at 4800 nmol nitrite and 480 nmol nitrate. The neuroprotective effects of nitrite were inhibited completely by the carboxy-PTIO. The 480 nmol nitrite attenuated dihydroethidium activity, 3-nitrotyrosine formation, and lipid peroxidation in the ischemic brain. CONCLUSIONS: Nitrite exerted profound neuroprotective effects with antioxidant properties in the ischemic brains. These results suggest that nitrite, as a biological storage reserve of NO, may be a novel therapeutic agent in the setting of acute stroke.This study was supported by a Korean Research Foundation grant funded by the Korean Government (MOEHRD, Basic Research Promotion Fund, KRF-2005-015-E00182)
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