Characterization of Astrocytes in the Minocycline-Administered Mouse Photothrombotic Ischemic Stroke Model.

Astrocytes, together with microglia, play important roles in the non-infectious inflammation and scar formation at the brain infarct during ischemic stroke. After ischemia occurs, these become highly reactive, accumulate at the infarction, and release various inflammatory signaling molecules. The regulation of astrocyte reactivity and function surrounding the infarction largely depends on intercellular communication with microglia. However, the mechanisms involved remain unclear. Furthermore, recent molecular biological studies have revealed that astrocytes are highly divergent under both resting and reactive states, whereas it has not been well reported how the communication between microglia and astrocytes affects astrocyte divergency during ischemic stroke. Minocycline, an antibiotic that reduces microglial activity, has been used to examine the functional roles of microglia in mice. In this study, we used a mouse photothrombotic ischemic stroke model to examine the characteristics of astrocytes after the administration of minocycline during ischemic stroke. Minocycline increased astrocyte reactivity and affected the localization of astrocytes in the penumbra region. Molecular characterization revealed that the induced expression of mRNA encoding the fatty acid binding protein 7 (FABP7) by photothrombosis was enhanced by the minocycline administration. Meanwhile, minocycline did not significantly affect the phenotype or class of astrocytes. The expression of Fabp7 mRNA was well correlated with that of tumor-necrosis factor α (TNFα)-encoding Tnf mRNA, indicating that a correlated expression of FABP7 from astrocytes and TNFα is suppressed by microglial activity.

Increased CD69 expression on activated eosinophils in eosinophilic chronic rhinosinusitis correlates with clinical findings.

BACKGROUND: Eosinophilic chronic rhinosinusitis (ECRS) is a subtype of chronic rhinosinusitis associated with asthma. CD69 is an important marker of activation for eosinophils. But, whether a correlation exist between the CD69 expression on eosinophils and clinical findings is unclear. METHODS: We performed quantitative PCR and/or flow cytometry using tissue and purified eosinophils from the blood and nasal polyps of 12 patients with ECRS and from 8 patients without ECRS (controls). We assessed clinical findings including nasal polyp (NP) scores, sinus CT findings, and pulmonary function test results, and examined their possible association with the CD69 expression. We also performed CD69 cross-linking experiments in mouse eosinophils to investigate the functional role of CD69. RESULTS: Levels of cytokine mRNAs (IL-4, -5, -10, and -13) were significantly higher in purified NP eosinophils and tissues from patients with ECRS than the levels of those in controls. The expressions of major basic protein (MBP), eosinophilic cationic protein (ECP), eosinophilic-derived neurotoxin (EDN), eosinophil peroxidase (EPX) in cytotoxic granules, and CD69 mRNA were significantly higher in purified eosinophils from NPs than in those from blood. We also found a correlation between expression of CD69 and clinical findings. Moreover, we found EPX release from mouse eosinophils following CD69 cross-linking. CONCLUSIONS: These data suggest that increased CD69 expression by eosinophils is not only a biomarker for nasal obstruction and pulmonary dysfunction, but also a potential therapeutic target for patients with ECRS and asthma.

Cells Expressing Prominin-1 in Neonatal Murine Inferior Colliculus Differentiate into Neurons and Glia.

Inferior colliculus (IC) is a major center for the integration and processing of acoustic information from ascending auditory pathways. Damage to the IC as well as normal aging can impair auditory function. Novel strategies such as stem cell (SC)-based regenerative therapy are required for functional recovery because mature neural cells have a minimal regenerative capacity after an injury. However, it is not known if there are neural stem cells (NSCs) in the IC. Herein, we screened for NSCs by surface marker analysis using flow cytometry. Isolated IC cells expressing prominin-1 (CD133) exhibited the cardinal NSC properties self-renewal capacity, expression of known NSC markers (SOX2 and nestin), and multipotency. Prominin-1-expressing cells from neonatal IC generated neurospheres, and culture of these neurospheres in differentiation-conditioned medium gave rise to gamma-aminobutyric acid-ergic (GABAergic) neurons, astrocytes, and oligodendrocytes. The presence of NSC-like cells in the IC has important implications for understanding IC development and for potential regenerative therapy.

Characterization of side population (SP) cells in murine cochlear nucleus.

CONCLUSION: We characterized side population (SP) cells in the cochlear nucleus (CN). Some genes of stem/progenitor markers in sorted SP cells were identified by microarray analysis and RT-PCR. Furthermore, some cells in the CN also demonstrated self-renewal and clonal expansion activities. These results suggest that tissue stem/ progenitor like cells would be identified and characterized as a slow cycling and immaturity in SP cells of CN. OBJECTIVES: SP cells were sorted and characterized as regards their activity in the CN in order to identify the tissue progenitor/stem cells in the auditory nervous system. METHODS: Bromodeoxyuridine (BrdU)-injected mice were prepared and the long-term BrdU-retaining cells were detected by flow cytometry. Gene expression of SP and MP cells was analyzed by microarray analysis and RT-PCR. SP cells were cultured in conditioned medium to expand stem/progenitor cells in vitro and to estimate the spheroid-forming activity of stem cells. RESULTS: In all, 1% of cells in the CN were detected as BrdU-positive. SP cells were detected at a frequency of 4.4% and expressed stem/progenitor markers, Abcb1b, Abcg2, Sca1, Notch1, Notch4, Hes1, and Jag1 in microarray analysis. Expression of Abcb1b, Abcg2, Sca1,Oct3/4, and Sox2 as determined by RT-PCR was supported by the microarray data. CN cells also had sphere-forming activity in young mice, but this activity was decreased by aging.

Pulsatile tinnitus as a first symptom of essential thrombocythemia.

Tinnitus is the sensation of sound inside the head and is a common symptom encountered daily by otorhinolaryngologists. Pulsatile tinnitus sufferers hear rhythmical noise at the same rate as a heartbeat and can present a diagnostic challenge. In this report, we present a 32-year-old patient with pulsatile tinnitus that led to the diagnosis of essential thrombocythemia. The symptom of pulsatile tinnitus allowed an early diagnosis of essential thrombocythemia and a more favorable prognosis. The case demonstrates the importance of blood tests for all patients who present with pulsatile tinnitus of unknown origin.