Publications by authors named "Tsuyoshi Nishioku"

Background: The recreational drug ±3,4-methylenedioxymethamphetamine (MDMA; also known as "ecstasy") has unusual subjective prosocial and empathogenic effects, and has exhibited potential as an adjunct to psychotherapy in recent years. However, there has been some concern regarding possible neuropsychiatric symptoms, such as cognitive impairment and dependence, emerging after abstinence. Therefore, this study aimed to evaluate the mechanism underlying cognitive impairment during MDMA withdrawal.

View Article and Find Full Text PDF

Osteoclasts are multinucleated, specializes bone-resorbing cells that are derived from the monocyte/macrophage lineage. Excessive resorbing activities of osteoclasts are involved in destructive bone diseases. The detailed mechanism of acidification at the bone adhesion surface during the bone resorption process of osteoclasts remains to be defined.

View Article and Find Full Text PDF

Nalmefene, an analog to naltrexone, is an antagonist at the μ opioid receptor and a partial agonist at the κ opioid receptor. Both agents are approved for the treatment of alcohol use disorder and opioid addiction. Here, we evaluated the potential of nalmefene for treating psychostimulant dependence using a methamphetamine (METH) self-administration rat model.

View Article and Find Full Text PDF

Osteoporosis disturbs the balance of bone metabolism, and excessive bone resorption causes a decrease in bone density, thus increasing the risk of fracture. (-)-Epigallocatechin-3-gallate (EGCG) is the most abundant catechin contained in green tea. EGCG has a variety of pharmacological activities.

View Article and Find Full Text PDF

Osteoclasts are multinucleated bone-resorbing cells derived from monocyte/macrophage progenitor cells. Excessive formation and resorbing activities of osteoclasts are involved in the bone-destructive pathologies of rheumatoid arthritis and osteoporosis. Recently, it has been found that nuclear factor erythroid 2-related factor 2 (Nrf2), a transcription factor for anti-oxidative stress genes, functions in osteoclastogenesis.

View Article and Find Full Text PDF

Berberine (BBR), an isoquinoline alkaloid, is a well-known bioactive compound contained in medicinal plants used in traditional and folk medicines. In this study, we investigated the subcellular localization and the apoptotic mechanisms of BBR were elucidated. First, we confirmed the incorporation of BBR into the cell visually.

View Article and Find Full Text PDF

CD147, a membrane glycoprotein of the immunoglobulin superfamily, is highly upregulated during dynamic cellular events including tissue remodelling. Elevated CD147 expression is present in the joint of rheumatoid arthritis patients. However, the role of CD147 in bone destruction remains unclear.

View Article and Find Full Text PDF

Background: BMP4, a member of the transforming growth factor-beta superfamily, is upregulated in the aortas of diabetic db/db mice. However, little is known about its role in diabetic atherosclerosis. Therefore, we examined the roles of BMP4 in the formation of diabetic atherosclerosis in apolipoprotein E knockout (ApoE KO) mice and in the uptake of oxidized low density lipoprotein (oxLDL) in peritoneal macrophages of wild-type mice.

View Article and Find Full Text PDF

The blood-brain barrier (BBB) is formed by brain endothelial cells. Many immortalized brain endothelial cell lines have been established; these have been used as in vitro BBB models. The aim of the present study was to assess the paracellular barrier properties of the immortalized mouse brain endothelial cell lines bEND.

View Article and Find Full Text PDF

Background: Cyclophilin A (CypA), a member of the immunophilin family, is a ubiquitously distributed intracellular protein. Recent studies have shown that CypA is secreted by cells in response to inflammatory stimuli. Elevated levels of extracellular CypA and its receptor, CD147 have been detected in the synovium of patients with RA.

View Article and Find Full Text PDF

Recently, 3-hydroxy-3-methyl glutaryl coenzyme A (HMG-CoA) reductase inhibitors were reported to induce neurite outgrowth in vitro. However, the mechanism underlying this effect remains unclear. Cellular prion protein (PrP(C)) is a ubiquitous glycoprotein present on the surfaces of various cells, including neurons, and is suggested to be involved in neurite outgrowth.

View Article and Find Full Text PDF

P-glycoprotein, an efflux transporter that is highly expressed at the blood-brain barrier (BBB), is involved in the traffic of several compounds across the BBB. BBB disruption under pathological conditions is observed in parallel with microglial activation. Previous studies of the interaction between rat brain endothelial cells (RBECs) and microglia have shown that lipopolysaccharide (LPS) activated microglia increase the permeability of RBECs through a mechanism involving NADPH oxidase.

View Article and Find Full Text PDF

Background: 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.

View Article and Find Full Text PDF

Olanzapine is known to be advantageous with respect to outcome and drug compliance in patients with schizophrenia. However, olanzapine has adverse effects, including a higher incidence of weight gain and metabolic disturbances, when compared with those of other antipsychotic agents. The mechanisms underlying these adverse events remain obscure.

View Article and Find Full Text PDF

The conversion of cellular prion protein (PrP(C)) to its protease-resistant isoform is involved in the pathogenesis of prion disease. Although PrP(C) is a ubiquitous glycoprotein that is present in various cell types, the physiological role of PrP(C) remains obscure. The present study aimed to determine whether PrP(C) mediates migration of brain microvascular endothelial cells.

View Article and Find Full Text PDF

Aims: Cyclosporin A, a calcineurin inhibitor, produces neurotoxicity with relatively high frequency in organ-transplanted patients. The aim of the present study was to clarify whether acute liver failure (ALF) simulated to the transient liver dysfunction at an early phase after liver transplantation increases the susceptibility to cyclosporin A-induced neurotoxicity through the blood-brain barrier (BBB) dysfunction.

Main Methods: The right internal, left lateral and left internal lobes in male ddy mice were surgically excised under sodium pentobarbital anesthesia.

View Article and Find Full Text PDF

The blood-brain barrier (BBB) is the interface that separates the central nervous system (CNS) from the peripheral circulation. An increase in blood-borne substances including cytokines in plasma and brain affects BBB function, and this is associated with the development of pathogenesis of a number of diseases. Plasminogen activator inhibitor (PAI)-1 regulates the plasminogen activator/plasmin system as a serpin in the periphery and the CNS.

View Article and Find Full Text PDF

Patients with rheumatoid arthritis (RA) are at higher risk of developing pathological cardiovascular and cerebrovascular events than non-RA subjects. Vascular endothelial dysfunction is involved in the induction of cardiovascular events and this process is also observed in patients with RA. Endothelial dysfunction impairs the integrity of the blood-brain barrier (BBB); this phenomenon also underlies brain damage in cerebrovascular diseases.

View Article and Find Full Text PDF

Cyclosporin A, a potent immunosuppressant, can often produce neurotoxicity in patients, although its penetration into the brain is restricted by the blood-brain barrier (BBB). Brain pericytes and astrocytes, which are periendothelial accessory structures of the BBB, can be involved in cyclosporin A-induced BBB disruption. However, the mechanism by which cyclosporin A causes BBB dysfunction remains unknown.

View Article and Find Full Text PDF

The present study was designed to elucidate the involvement of tumor necrosis factor-alpha (TNF-alpha) release from activated microglia in the induction of blood-brain barrier (BBB) dysfunction in an in vitro co-culture system with mouse brain capillary endothelial cells (MBEC4) and microglia. Lipopolysaccharide (LPS)-activated microglia increased the permeability of MBEC4 cells to sodium-fluorescein, and this hyper-permeability was blocked by a neutralizing antibody against TNF-alpha. LPS stimulated microglia to facilitate TNF-alpha release.

View Article and Find Full Text PDF

The blood-brain barrier (BBB) is formed by brain capillary endothelial cells, astrocytes, pericytes, microglia, and neurons. BBB disruption under pathological conditions such as neurodegenerative disease and inflammation is observed in parallel with microglial activation. To test whether activation of microglia is linked to BBB dysfunction, we evaluated the effect of lipopolysaccharide (LPS) on BBB functions in an in vitro co-culture system with rat brain microvascular endothelial cells (RBEC) and microglia.

View Article and Find Full Text PDF
Article Synopsis
  • Blockade of ANG II AT(1) receptors using candesartan in normotensive rats reduced the inflammatory response triggered by bacterial endotoxin LPS.
  • Administration of LPS resulted in higher levels of inflammatory cytokines (TNF-alpha, IL-1beta, IL-6) in circulation, but candesartan pretreatment significantly decreased their release.
  • The study concludes that AT(1) receptors play a crucial role in the innate immune response to endotoxins and suggests that ARBs could potentially offer therapeutic benefits for inflammatory diseases.
View Article and Find Full Text PDF

The blood-brain barrier (BBB) is highly restrictive of the transport of substances between blood and the central nervous system. Brain pericytes are one of the important cellular constituents of the BBB and are multifunctional, polymorphic cells that lie within the microvessel basal lamina. The present study aimed to evaluate the role of pericytes in the mediation of BBB disruption using a lipopolysaccharide (LPS)-induced model of septic encephalopathy in mice.

View Article and Find Full Text PDF

Brain pericytes are known to embrace the abluminal endothelial surfaces of cerebral microvessels. The rich expression of contractile proteins in these cells suggests pericytal regulation of cerebral blood flow. Here, we investigated the molecular mechanisms by which an endothelium-derived relaxing factor, adrenomedullin, was able to induce the relaxation of rat primary cultured brain pericytes.

View Article and Find Full Text PDF

To clarify the role of Angiotensin II in the regulation of peripheral sensory and motor systems, we initiated a study of the expression, localization and transport of Angiotensin II receptor types in the rat sciatic nerve pathway, including L(4)-L(5) spinal cord segments, the corresponding dorsal root ganglia (DRGs) and the sciatic nerve. We used quantitative autoradiography for AT(1) and AT(2) receptors, and in situ hybridization to detect AT(1A), AT(1B) and AT(2) mRNAs. We found substantial expression and discrete localization of Angiotensin II AT(1) receptors, with much higher numbers in the grey than in the white matter.

View Article and Find Full Text PDF