Three principal cell types in the central nervous system, i.e., neurons, astrocytes and oligodendrocytes, arise from neural stem cells. Recent studies have revealed that such stem cells are present in the adult brain as well as in the developing brain. Recent advances enabled us to understand molecular regulation of neural stem cells, raising a possibility that they can be used for therapeutic treatment of neurodegenerative diseases. Differentiation of neural stem cells into the three neural cell types is known to be regulated in part by cell-external cues. For example, cytokines in the interleukin-6 (IL-6) family and the transforming growth factor β (TGF β) family promote astrocytogenesis. In the nucleus of cytokine-treated cells, multiple physical interactions among transcription factors and transcriptional co-activators occur and contribute to the neuroglial differentiation. Upon injury, cytokines secreted from injured tissues affect cell fates of neighboring stem cells during nerve regeneration in the adult. In this case, undesired gliosis is often observed, which is most likely induced by such cytokines. In addition to cell-external cues, cell fate determination process is also regulated by cell-intrinsic programs, which include epigenetic regulation. Spationtemporally regulated expression of lineage specific genes are important for fate determination of neural stem cells, which in some cases is associated with DNA methylation and histone modification within their promoters. From these viewpoints, we here discuss molecular regulation of neural stem cells during development and regeneration. Efforts to apply our findings to therapeutic treatment of neurodegenerative disorders are also discussed.

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Nonsteroidal anti-inflammatory drugs (NSAIDs) inhibit the cyclooxygenase (COX) enzyme and suppress PG synthesis which are used commonly as anti-inflammatory, anti-pyretic and analgestic agents. Though NSAIDs is known to suppress incidence and progression of cancer especially colorectal cancer, the precise mechanism of their protective effect remain unknown. A wide range of mechanism about anti-tumor effect of NSAIDs have been reported. Some of them are unrelated to the inhibition of COX activity and subsequent PG formation. However, recent result from by using knockout mice and selective antagonists indicated that prostanoid receptor, especially PGE₂ enhances angiogenesis and tumor growth. Here, we summarize significant of PGE₂ signaling via EP3 receptors which exists on the stroma but on tumor cells. An EP3 receptor antagonist may be a candidate of chemopreventive agents for malignant tumor.

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Dermal circulation is affected by age, changes in the environmental conditions, and diseases. To measure the dermal circulation, laser Doppler flowmeters (LDF) are used in the clinical and research fields, but there are problems; for example, evaluation of blood circulation in the whole tissues is difficult because the probe (PB) has to be fixed at a site of the skin. In this study, to solve these problems, we attempted to develop a new flowmeter, and evaluated basic data and its clinical application.
We developed a contact type LDF equipped with a thermal loading device, and evaluated its clinical application. In the PB of this apparatus, 7 transmission and reception fiber units (FU) were arranged on the measurement surface with a diameter of 16 mm, and integrated with the heating and cooling Pertier's elements, by which temperature in the flowmeter can be controlled, and fluctuations of blood flow signals were averaged.
To evaluate dermal vasomotor function using this apparatus, several sites in 10 healthy females in their 20s were transiently (2min) cooled (10°C), and changes in the blood circulation were measured before, during, and after the cooling period.
Nine parameters, such as the mean blood flow when the dermal surface was maintained at 30°C for 1 min (F_30°C) and the minimal blood flow when the dermal surface was maintained at 10°C for 2min (F_min), were used for analysis, and the dermal microcirculation was classified into types A (in the palms), B (in the cheeks), and C (in the forearms). The results agreed well with the known distribution of blood vessels and density of nerves.
We developed a contact type 64-channel two-dimensional laser Doppler flowmeter (64-Ch LDF), and evaluated its clinical application. To measure the two-dimensional changes in the blood flow in a fixed dermal region, we developed a 64-Ch LDF equipped with a contact type PB, in which 64FU were arranged to form an 8×8 matrix at intervals of 2mm.
To evaluate the clinical application of this apparatus, the hemodynamic changes caused by Valsalva's treatment of microcirculation on the palm were examined. It was found that the distribution of blood flow in the measurement region changed with the physiological treatment, indicating that this apparatus was useful for the evaluation of hemodynamics.
In the future, we will perform clinical studies of vascular diseases and studies on microcirculation improving drugs, and our apparatus will provide a new evaluation method.

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Hematopoietic prostaglandin D synthase (PGDS) is a key enzyme to produce prostaglandin (PG) D and J series. These PGs are involved in inflammation and immune system. While PGD₂ mediates sleep and allergic reaction in asthma, the non-enzymatic metabolite, 15-deoxy-Δ^12,14-PGJ₂ displays several anti-inflammatory effects. Since the PGs are structurally labile and instable in body, constitutive expression of the producing enzyme, PGDS would be expected to evaluate biological activities of PGD₂ and PGJ series. To determine whether introduction of PGDS exerts proinflammatory or anti-inflammatory effect, human hematopoietic PGDS complementary DNA-expressing retrovirally transfected fibroblasts were introduced in vivo, and effects of the introduction on several inflammatory models were investigated. Introduction of PGDS-expressing fibroblasts effectively attenuated carrageenin-induced paw edema as an acute inflammatory model and formation of granuloma and angiogenesis in sponge-implanted model as a chronic inflammatory model, suggesting the introduction could be anti-inflammatory. Moreover, expression of PGDS decreased generation of chemokines followed by decreased infiltration of leukocytes in sodium urate monohydrate crystal-induced acute inflammation using air-pouch model in mice, and suppressed fibrosis with reduced expression of cytokines and growth factors in bleomycin-induced lung injury. These results suggest a potential cell therapy for such pathogenesis by PGDS-expressing cells.

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The neurosphere method is widely used to examine self-renewal activity and the multipotency of neural stem cells (NSCs). We developed an efficient method for introducing a transgene into neurospheres using a retroviral vector and isolating a transgenic subpopulation of NSCs labeled with green fluorescent protein (GFP) using fluorescence-activated cell sorting, enabling these cells to be used in subsequent biological assays. This method is expected to be useful for studying the function of genes in NSCs.

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It has been increasingly recognized that Chlamydia pneumoniae may be involved in the pathogenesis of atherosclerosis; accordingly, detection of this bacterium in blood from atherosclerotic patients may play an important role in diagnosis of possible complications of atherosclerosis including stroke. However, there is little understanding about the detection incidence of C. pneumoniae in the blood of stroke patients. In the present study, we performed the PCR specific for C. pneumoniae 16S rRNA to determine the C. pneumoniae DNA in peripheral blood mononuclear cells (PBMCs) obtained from patients with atherothrombotic infarction. C. pneumoniae DNA was detected in 5 out of 13 blood samples from the patients with atherothrombotic infarction. These results indicate a possible correlation between C. pneumoniae infection and atherothrombotic infarction attributable to atherosclerosis.

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Matrix metalloproteinase-3 (MMP-3) is a proteolytic enzyme produced by synovial cells, participating in the joint destruction.
To investigate the clinical significance of serum MMP-3 level in patients with rheumatoid arthritis (RA), we compared MMP-3 level with other clinical parameters of disease activity in 99 patients with RA. Sixty-two patients were positive for MMP-3. Both serum level of C-reactive protein (CRP) and the Lansbury articular index were significantly higher in the group of patients positive for MMP-3 compared to that of patients negative for MMP-3. Serum MMP-3 level was shown to be correlated with serum level of CRP and the Lansbury articular index, but not with tender joint count nor swollen joint count. Thus, our results strongly support the idea that serum MMP-3 level is a useful indicator of arthritic activity in patients with RA.

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