Brain pericytes among cells constituting the blood-brain barrier are highly sensitive to tumor necrosis factor-α, releasing matrix metalloproteinase-9 and migrating in vitro

<p>Abstract</p> <p>Background</p> <p>Increased matrix metalloproteinase (MMP)-9 in the plasma and brain is associated with blood-brain barrier (BBB) disruption through proteolytic activity in neuroinflammatory diseases. MMP-9 is present in the brain microvasculature and its vicinity, where brain microvascular endothelial cells (BMECs), pericytes and astrocytes constitute the BBB. Little is known about the cellular source and role of MMP-9 at the BBB. Here, we examined the ability of pericytes to release MMP-9 and migrate in response to inflammatory mediators in comparison with BMECs and astrocytes, using primary cultures isolated from rat brains.</p> <p>Methods</p> <p>The culture supernatants were collected from primary cultures of rat brain endothelial cells, pericytes, or astrocytes. MMP-9 activities and levels in the supernatants were measured by gelatin zymography and western blot, respectively. The involvement of signaling molecules including mitogen-activated protein kinases (MAPKs) and phosphoinositide-3-kinase (PI3K)/Akt in the mediation of tumor necrosis factor (TNF)-α-induced MMP-9 release was examined using specific inhibitors. The functional activity of MMP-9 was evaluated by a cell migration assay.</p> <p>Results</p> <p>Zymographic and western blot analyses demonstrated that TNF-α stimulated pericytes to release MMP-9, and this release was much higher than from BMECs or astrocytes. Other inflammatory mediators [interleukin (IL)-1β, interferon-γ, IL-6 and lipopolysaccharide] failed to induce MMP-9 release from pericytes. TNF-α-induced MMP-9 release from pericytes was found to be mediated by MAPKs and PI3K. Scratch wound healing assay showed that in contrast to BMECs and astrocytes the extent of pericyte migration was significantly increased by TNF-α. This pericyte migration was inhibited by anti-MMP-9 antibody.</p> <p>Conclusion</p> <p>These findings suggest that pericytes are most sensitive to TNF-α in terms of MMP-9 release, and are the major source of MMP-9 at the BBB. This pericyte-derived MMP-9 initiated cellular migration of pericytes, which might be involved in pericyte loss in the damaged BBB.</p

Laser-induced fluorescence imaging of plants using a liquid crystal tunable filter and charge coupled device imaging camera

ArticleReview of Scientific Instruments. 76, 106103 (2005)journal articl

Functional Analysis of Dendritic Cells Generated from T-iPSCs from CD4+ T Cell Clones of Sjögren\u27s Syndrome

Although it is important to clarify the pathogenic functions of T cells in human samples, their examination is often limited due to difficulty in obtaining sufficient numbers of dendritic cells (DCs), used as antigen-presenting cells, especially in autoimmune diseases. We describe the generation of DCs from induced pluripotent stem cells derived from T cells (T-iPSCs). We reprogrammed CD4+ T cell clones from a patient with Sjögren\u27s syndrome (SS) into iPSCs, which were differentiated into DCs (T-iPS-DCs). T-iPS-DCs had dendritic cell-like morphology, and expressed CD11c, HLA-DR, CD80, CD86, and also BDCA-3. Compared with monocyte-derived DCs, the capacity for antigen processing was similar, and T-iPS-DCs induced the proliferative response of autoreactive CD4+ T cells. Moreover, we could evaluate T cell functions of the patient with SS. In conclusion, we obtained adequate numbers of DCs from T-iPSCs, which could be used to characterize pathogenic T cells in autoimmune diseases such as SS

Post-intervention Status in Patients With Refractory Myasthenia Gravis Treated With Eculizumab During REGAIN and Its Open-Label Extension

OBJECTIVE: To evaluate whether eculizumab helps patients with anti-acetylcholine receptor-positive (AChR+) refractory generalized myasthenia gravis (gMG) achieve the Myasthenia Gravis Foundation of America (MGFA) post-intervention status of minimal manifestations (MM), we assessed patients' status throughout REGAIN (Safety and Efficacy of Eculizumab in AChR+ Refractory Generalized Myasthenia Gravis) and its open-label extension. METHODS: Patients who completed the REGAIN randomized controlled trial and continued into the open-label extension were included in this tertiary endpoint analysis. Patients were assessed for the MGFA post-intervention status of improved, unchanged, worse, MM, and pharmacologic remission at defined time points during REGAIN and through week 130 of the open-label study. RESULTS: A total of 117 patients completed REGAIN and continued into the open-label study (eculizumab/eculizumab: 56; placebo/eculizumab: 61). At week 26 of REGAIN, more eculizumab-treated patients than placebo-treated patients achieved a status of improved (60.7% vs 41.7%) or MM (25.0% vs 13.3%; common OR: 2.3; 95% CI: 1.1-4.5). After 130 weeks of eculizumab treatment, 88.0% of patients achieved improved status and 57.3% of patients achieved MM status. The safety profile of eculizumab was consistent with its known profile and no new safety signals were detected. CONCLUSION: Eculizumab led to rapid and sustained achievement of MM in patients with AChR+ refractory gMG. These findings support the use of eculizumab in this previously difficult-to-treat patient population. CLINICALTRIALSGOV IDENTIFIER: REGAIN, NCT01997229; REGAIN open-label extension, NCT02301624. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that, after 26 weeks of eculizumab treatment, 25.0% of adults with AChR+ refractory gMG achieved MM, compared with 13.3% who received placebo

Minimal Symptom Expression' in Patients With Acetylcholine Receptor Antibody-Positive Refractory Generalized Myasthenia Gravis Treated With Eculizumab

The efficacy and tolerability of eculizumab were assessed in REGAIN, a 26-week, phase 3, randomized, double-blind, placebo-controlled study in anti-acetylcholine receptor antibody-positive (AChR+) refractory generalized myasthenia gravis (gMG), and its open-label extension

Elevated end-diastolic ratio of the common carotid artery due to cerebral arteriovenous malformation: Two case reports

An elevated end-diastolic (ED) ratio of the common carotid artery (CCA) is an indicator of occlusive lesions of the distal portion of the internal carotid artery. We report 2 cases of cerebral arteriovenous malformation (AVM) showing an elevated ED ratio of the CCA, which decreased after surgery. Case 1 was a 28-year-old man with chronic recurrent headache with aura, and case 2 was a 29-year-old woman with sudden-onset headache and intracerebral hemorrhage without neurologic abnormality. In both cases, digital subtraction angiography revealed a Spetzler-Martin Grade IV AVM, which was mainly fed by branches of the left middle cerebral artery with venous drainage into superficial and deep cerebral veins. Preoperative carotid ultrasonography showed an elevated CCA ED ratio (1.38 in case 1 and 1.47 in case 2; left > right) without atherosclerotic lesions. Patients’ AVMs were successfully resected. In both cases, the ED ratio was decreased after surgery (to 1.05 in case 1 and 1.20 in case 2). A decrease in vascular resistance on 1 side caused by cerebral AVM can result in an increase in the CCA ED ratio comparable to that of carotid axis occlusion. Keywords: Carotid ultrasonography, Cerebral arteriovenous malformation, End-diastolic rati

Scleroderma Renal Crisis Complicated with Thrombotic Microangiopathy Triggered by Influenza B Virus Infection

A 44-year-old Japanese man with a 14-year history of limited cutaneous systemic sclerosis (SSc) was admitted with a fever, hypertension, anemia, thrombocytopenia, and renal dysfunction. On admission, hypertension, hyperreninemia, acute renal dysfunction,hemolytic anemia, and thrombocytopenia led to the diagnosis of scleroderma renal crisis (SRC) complicated with thrombotic microangiopathy (TMA). The patient had also been infected with influenza B virus almost six days before admission. Following treatment with plasma exchange,an angiotensin-converting enzyme inhibitor, and an anti-virus agent, his general condition improved. He had no risk factors for SRC.In SSc patients, an influenza virus infection might trigger SRC complicated with TMA