Satoru Koyanagi

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Because angiogenesis is essential for tumor growth and metastasis, inhibition of angiogenesis has emerged as a new therapy to treat cancers. Hypoxia-induced expression of vascular endothelial growth factor (VEGF) plays a central role in tumor-induced angiogenesis. In this study, we found that expression of VEGF in hypoxic tumor cells was affected by the(More)
Fucoidan, a sulfated polysaccharide extracted from brown seaweed, has anticoagulant and antithrombotic activities. Unlike heparin, it shows an inhibitory action on the progression and metastasis of malignant tumors, although the precise mechanisms have not been elucidated. We have demonstrated previously that fucoidan can inhibit tube formation following(More)
BACKGROUND & AIMS P-glycoprotein, the product of the multidrug resistance (mdr) gene, functions as a xenobiotic transporter contributing to the intestinal barrier. Although intestinal expression of the mdr1a gene and its efflux pump function has been shown to exhibit 24-hour variation, the mechanism of the variations remains poorly understood. Here, we(More)
Neuropathic pain, a debilitating pain condition, is a common consequence of damage to the nervous system. Optimal treatment of neuropathic pain is a major clinical challenge because the underlying mechanisms remain unclear and currently available treatments are frequently ineffective. Emerging lines of evidence indicate that peripheral nerve injury converts(More)
Microglia are thought to play important roles in the maintenance of neuronal circuitry and the regulation of behavior. We found that the cortical microglia contain an intrinsic molecular clock and exhibit a circadian expression of cathepsin S (CatS), a microglia-specific lysosomal cysteine protease in the brain. The genetic deletion of CatS causes mice to(More)
Parkinson’s disease (PD) is a common neurodegenerative disorder that is characterized by the degeneration of dopaminergic neurons in the substantia nigra and dopamine depletion in the striatum. Although the motor symptoms are still regarded as the main problem, non-motor symptoms in PD also markedly impair the quality of life. Several non-motor symptoms,(More)
DEC1 (BHLHB2/Sharp2/Stra13) and DEC2 (BHLHB3/Sharp1) are basic-helix-loop-helix (bHLH) transcription factors, involved in cellular differentiation, responses to hypoxia and circadian rhythms. We recently showed that the expression of DEC1 and DEC2 was up-regulated by hypoxia; however, the functions of these two factors under hypoxic conditions have not been(More)
Activating transcription factor (ATF)/cAMP-response element (CRE)-binding (CREB) proteins induce the CRE-mediated gene transcription depending on the cAMP stimulation. cAMP-dependent signaling oscillates in a circadian manner, which in turn also sustains core oscillation machinery of the circadian clock. Here, we show that among the ATF/CREB family(More)
One of the most indispensable biological functions for all living organisms is the circadian clock, which acts like a multifunctional timer to regulate the homeostatic system, including sleep and wakefulness, hormonal secretions, and various other bodily functions with a 24-h cycle. We reported previously that interferon (IFN) has the ability to modulate(More)
Although altered homeostatic regulation, including disturbance of 24-h rhythms, is often observed in the patients undergoing glucocorticoid therapy, the mechanisms underlying the disturbance remains poorly understood. We report here that chronic treatment with a synthetic glucocorticoid, prednisolone (PSL), can cause alteration of circadian clock function(More)