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71.
Calpain 7 (also known as PalBH) is a mammalian homologue of the Aspergillus, atypical calpain PalB. Knowledge of the biochemical properties of calpain 7 is limited and its function is not yet known. In this study, we investigated the interactions of calpain 7 with all 11 ESCRT-III-related proteins, named charged multivesicular body proteins (CHMPs), and the subcellular localization of calpain 7. Pulldown assays using stable HEK293T transfectants of Strep-tagged calpain 7 revealed interactions of calpain 7 with a subset of FLAG-tagged CHMPs, among which CHMP1B was selected for further analyses. The N-terminal region containing a tandem repeat of MIT domains of calpain 7 was found to be necessary and sufficient for interaction with CHMP1B. Direct interaction was confirmed by a pulldown assay using recombinant proteins. Fluorescence microscopic analysis using HeLa cells revealed that overexpression of GFP-fused CHMPs or a dominant-negative construct of SKD1/Vps4B caused accumulation of epitope-tagged calpain 7 in a punctate pattern in the perinuclear area. Subcellular fractionation revealed that the most of endogenous calpain 7 is present in the cytosol but a small portion is present in particulate fractions. Punctate fluorescence signals of monomeric GFP-fused calpain 7 partly merged with those of endocytosed tetramethylrhodamine-labelled EGF. These results suggest that calpain 7 plays roles in the endosomal pathway by interacting with a subset of ESCRT-III-related proteins.  相似文献   
72.
Vasodilative effect of perillaldehyde on isolated rat aorta   总被引:2,自引:0,他引:2  
The vasodilative effect of perillaldehyde, one of the major oil components in Perilla frutescens BRITTON, was studied using isolated rat aorta. Perillaldehyde at final concentrations of 0.01 to 1 mM showed dose-dependent relaxation of the aorta contracted by treatment with prostaglandin F2alpha or norepinephrine. Neither the presence of NG-nitro-L-arginine methyl ester nor removal of the aortic endothelium affected the vasodilatation, suggesting that perillaldehyde exerts a direct effect on vascular smooth muscle cells. The vasodilative effect of perillaldehyde was not inhibited by pretreatment with a beta-adrenergic receptor blocker (propranolol), an inhibitor of phosphodiesterase (theophylline), a delayed rectifier K+ channel blocker (tetraethylammonium chloride), or an ATP-sensitive K+ channel blocker (glibenclamide). However, perillaldehyde showed contrasting effects on vasodilatation of the aorta contracted by an influx of extracellular Ca2+ - perillaldehyde caused little vasodilatation on the aorta contracted by the Ca2+ ionophore A23187, while it inhibited the vasoconstriction induced by treatment with high-concentration K+, which dominantly opened the voltage-dependent Ca2+ channel. These results suggest that the vasodilative effect of perillaldehyde is derived from blocking the Ca2+ channels.  相似文献   
73.
We found that a herbal medicine (Mao-to) relieves the side effects of interferon (IFN)-beta and the combination therapy improves the biochemical response rate. However, the exact mechanism by which Mao-to is effective remains to be established. We conducted a controlled trial to clarify the effects of Mao-to. The study was carried out in 18 patients with chronic hepatitis C, and we examined subjective symptoms, body temperature and cytokines such as interleukin (IL)-beta, IL-1receptor antagonist (ra), IL-6 and TNF-alpha. Each patient received 6 million units of IFN-beta intravenously. Mao-to was given orally just before, just after, and 1 hour after IFN administration. The control study was carried out 6 months after the combination therapy of Mao-to and IFN-beta. The scores for general malaise, arthralgia and discomfort were significantly lower in the combination group than in control group. Body temperature did not significantly differ between the two groups. Plasma IL-6 level and IL-1ra were significantly elevated in the combination group compared to control (P = 0.0057 and 0.0003, respectively). Mao-to did not affect plasma concentrations of IL-1beta and TNF-alpha. We considered the increment of IL-1ra caused by Mao-to is to be one of the key factors involved in reducing the flu-like symptoms accompanying IFN-beta and improving the biochemical response rate.  相似文献   
74.
Mammalian or mechanistic target of rapamycin complex 1 (mTORC1) is a master regulator of cell growth, metabolism, and cell differentiation. Recent studies have revealed that the recruitment of mTORC1 to lysosomes is essential for its activation. The ceramide analogue 1-phenyl-2-decanoylamino-3-morpholino-1-propanol (PDMP), a well known glycosphingolipid synthesis inhibitor, also affects the structures and functions of various organelles, including lysosomes and endoplasmic reticulum (ER). We investigated whether PDMP regulates the mTORC1 activity through its effects on organellar behavior. PDMP induced the translocation of mTORC1 from late endosomes/lysosomes, leading to the dissociation of mTORC1 from its activator Rheb in MC3T3-E1 cells. Surprisingly, we found mTORC1 translocation to the ER upon PDMP treatment. This effect of PDMP was independent of its action as the inhibitor, since two stereoisomers of PDMP, with and without the inhibitor activity, showed essentially the same effect. We confirmed that PDMP inhibits the mTORC1 activity based on the decrease in the phosphorylation of ribosomal S6 kinase, a downstream target of mTORC1, and the increase in LC3 puncta, reflecting autophagosome formation. Furthermore, PDMP inhibited the mTORC1-dependent osteoblastic cell proliferation and differentiation of MC3T3-E1 cells. Accordingly, the present results reveal a novel mechanism of PDMP, which inhibits the mTORC1 activity by inducing the translocation of mTOR from lysosomes to the ER.  相似文献   
75.
Choto-san is a formula used for the treatment of headache and vertigo. Recently it has often also been used for hypertension and dementia. One of the mechanisms involved is thought to be the improvement of blood circulation, but the details are still unclear. In this study, the effect of Chotosan was studied on nitric oxide (NO) function, hemorheological factors and endothelial function in stroke-prone spontaneously hypertensive rats (SHR-SP). Rats were given Choto-san in drinking water for eight weeks. Body weight, blood pressure, serum NO2-/NO3-, lipid peroxides, blood viscosity, erythrocyte deformability and endothelium-dependent/-independent relaxation were measured. The results indicated that Choto-san caused a decrease in blood pressure and an increase in erythrocyte deformability and NO function. Blood viscosity was not changed. Furthermore, endothelium-dependent relaxation by acetylcholine was significantly increased as compared to control. In this study, it was supposed that Choto-san had a protective effect on the endothelium. SHR-SP is a useful model for human brain stroke, and Choto-san showed a protective effect against cerebral vascular injury in the susceptible rat.  相似文献   
76.
The present study is designed to test our hypothesis that the ingestion of Uncaria sinensis (US), the main medicinal plant of Choto-san (Diao-teng-san, CS), would protect red blood cell (RBC) membrane from free radical-induced oxidation if polyphenolics in US could be absorbed and circulated in blood. When incubated with RBC suspension, Choto-san extract (CSE) and Uncaria sinensis extract (USE) exhibited strong protection for RBC membrane against hemolysis induced by 2,2-azo-bis (2-amidinopropane) dihydrochloride (AAPH), an azo free-radical initiator. The inhibitory effect was dose-dependent at concentrations of 50 to 1000 microg/mL. Ingestion of 200 mg of USE was associated with a significant decrease in susceptibility of RBC to hemolysis in rats. Furthermore, caffeic acid, an antioxidative hydroxycinnamic acid, was identified in rat plasma after administration of URE.  相似文献   
77.
We attempted to establish an enzyme-linked immunosorbent assay (ELISA) system by preparation of recombinant murine MIP-2 and its rabbit antibodies. A fusion construct of MIP-2 to protein A was used to enable easy purification as well as the generation of a sufficiently large antibody response. The specificity of antibody was confirmed by Western blotting analysis of 20-h conditioned medium from lipopolysaccharide (LPS)-stimulated RAW264.7 cells, a murine macrophage cell line; antibody gave a single band with a molecular weight of approximately 6000, which is identical to that of murine MIP-2 reported previously. Biotin-streptavidin sandwich ELISA could detect quantitatively MIP-2 at concentration range of 20 to 1000 pg/ml. In some applications of this ELISA system, time-related production of MIP-2 and inhibitory effect of dexamethasone on its production have been demonstrated in LPS-stimulated RAW264.7 cells. Thus, ELISA system established in this study is considered to be a useful tool to study MIP-2 response in various inflammation models in mice.  相似文献   
78.
We have cloned a rat kidney thromboxane A2 receptor (TP) cDNA. This receptor was shown to be functional in that the thromboxane A2 mimetics, U46619 and 1-BOP, elicited calcium transients in Xenopus oocytes and HEK293 cells expressing the TP receptor, respectively. Comparison of the affinities of the rat and human TP sites for the agonist radioligand [125I]BOP showed that the rat TP site has about a ten-fold higher affinity for this drug (KD = 0.5 vs. 4.4 nM) while the affinities of the two sites for other compound (U46619, I-PTH-OH) were the same. Our results are significant in that they identify a cloned TP as having a picomolar affinity for [125I]BOP.  相似文献   
79.
In order to characterize temporal pattern sensitivity in the cat ganglion cells, a new analysis technique by semi-Markov models which was developed in the previous papers (Tsukada et al., 1975–1977) was applied to input-output relations of the receptive-field. Three types of statistical spot stimuli positioned in the center region of receptive fields were used. Each type of stimulus has an identical histogram in the inter-stimulus intervals and therefore the same mean and variance, but different correlations between adjacent inter-stimulus intervals (Type 1, positive; Type 2, negative; and Type 3, independent processes). From the output spike trains of cat retinal ganglion cells to each stimulus, mean, variance, and histogram were computed. As the result of investigating these data, we could draw the following conclusion from the resultant output interval histograms. The receptive-field-center responses of cat ganglion cells can be classified into two groups (Types L and N) according to the difference of responsiveness to the three types of statistical spot stimuli. A Type L response has the same histogram in interspike intervals for all three stimuli, and is not sensitive to the temporal pattern, while a Type N response has three different forms depending on each type of stimulus showing high sensitivity to the temporal pattern. These results were also simulated by the Markov chain model and discussed with relation to neural coding and classification of ganglion cell types.  相似文献   
80.
Keishi-bukuryo-gan (Gui-zhi-fu-ling-wan) is a formula used for the improvement of blood circulation. Recently it has often also been used for arteriosclerosis. One of the mechanisms involved is thought to be the improvement of endothelial dysfunction, but the details are still unclear. In this study, the effect of Keishi-bukuryo-gan on vascular function and hemorheological factors in spontaneously diabetic (WBN/kob) rats was studied. Rats were given Keishi-bukuryo-gan in chow for 30 weeks. Body weight, blood glucose, endothelium-dependent/-independent relaxation, vasocontraction by free radical-induced and contractive prostanoids, triglyceride, advanced glycation endproduct, lipid peroxides, serum NO2-/NO3- and blood viscosity were measured. The results indicated that Keishi-bukuryo-gan caused a decrease in endothelium-dependent relaxation by acetylcholine to become significantly increased, and vasocontraction induced by free radicals and contractive prostanoids was significantly decreased. Furthermore, serum NO2-/NO3- and blood viscosity were significantly decreased. From these results, it was supposed that Keishi-bukuryo-gan exerted a protective effect on the endothelium. The WBN/kob rat is a useful study model for the complications of human diabetes, and Keishi-bukuryo-gan showed a protective effect against vascular injury in the susceptible rat.  相似文献   
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