Elevated plasma homocysteine is a risk factor for atherosclerotic disease. In the present study, we have examined whether the oxidative stress due to a low level of vitamin B 6 accelerates the development of homocysteine-induced atherosclerosis in rats. First, the effect of homocysteine thiolactone intake (50 mg/kg per d) on vascular integrity, lipid peroxide concentration, endothelial NO synthase (eNOS) expression and biochemical profiles was examined at day 1, day 21 and day 42 (five rats per group). The histochemical staining of the rat aorta showed no change at day 1 and day 21, but the subendothelial space was observed to be enlarged in rat aorta at day 42 with exposure to homocysteine thiolactone. Expression of eNOS was observed in rat aorta at day 42, but not at day 1 and day 21. Serum lipid peroxide concentration and biochemical profiles including glucose cholesterol and triacylglycerol showed no change at any day. Second, the effect of homocysteine thiolactone intake in the presence and absence of vitamin B 6 on vascular integrity was examined at day 1 and day 14 (five rats per group). Aortic lesions were observed in vitamin B 6 -deficient rat aorta at day 14 but not in vitamin B 6 -supplemented rats. The expression of eNOS was also observed in vitamin B 6 -deficient rat aorta at day 14. Serum lipid concentrations of the vitamin B 6 -deficient group significantly increased compared with concentrations of the vitamin B 6 -supplemented group, though serum concentration of homocysteine did not change between both groups. These results suggest that the oxidative stress caused by a low level of vitamin B 6 accelerates the development of homocysteine-induced atherosclerosis in rats.
Perchloric acid-soluble protein (PSP) is highly conserved during evolution from bacteria to mammals. Although PSP has been recognized as an inhibitor of translation and proliferation in vitro, its precise biological role has not yet been elucidated. Since we previously found similar distributions for PSP and the endoplasmic reticulum (ER) and Golgi complex, the intracellular distribution of PSP was analyzed in more detail. Immunofluorescence studies indicated that PSP co-localized with the ER and Golgi complex, since the distribution pattern of PSP was well matched to both of these organelles. An immunoelectron microscopic study revealed PSP was located not only in the cytosol but also on the surface of the outer ER membrane. Since PSP was present on the ER, we speculated that it may be associated with ER function. Therefore, we analyzed whether or not the ER stress response, which is one of the ER functions, affected PSP expression. The results showed that various ER stressors (thapsigargin, A23187, tunicamycin, brefeldin A, and cisplatin) provoked a dramatic change in the localization of PSP from outside of the nucleus to inside the nucleus within 3 h. Moreover, the ER stressors induced PSP expression. These results suggest that PSP is involved in the cellular response to ER stressors, and that the change in localization of PSP from the ER to the nucleus may be associated with ER stress responses.Keywords: perchloric acid; soluble protein; m-calpain; endoplasmic reticulum; ER stress; thapsigargin Perchloric acid-soluble protein (PSP) was initially isolated from the rat liver as a translational inhibitor (Oka et al. 1995). Subsequently, it was also found in various other species, including humans (Schmiedeknecht et al. (Kaneki et al. 2003b), and so on. Since its gene (a member of the YER057c/YJGF family) is highly conserved during evolution, PSP may play important roles in the cell. In mammals, PSP has been reported to be associated with various functions, including ribonuclease activity (Morishita et al. 1999;Sawasaki et al. 2001), fatty acid-binding activity (Sasagawa et al. 1999), differentiation-dependent expression (Oka et al. 1995;Asagi et al. 1998;Nordin et al. 2001;Suzuki et al. 2001;Kaneki et al. 2003a), and repression of proliferation . However, the precise biological function of PSP has not yet been elucidated. Reprint requests to: Hiroaki Kanouchi, Department of Biochemistry, Kawasaki Medical School, 577 Matsushima, Kurashiki-city, Okayama, 701-0192, Japan; e-mail: kanouchihiroaki@mac.com; fax: +81-86-462-1199.Abbreviations: PSP, perchloric acid-soluble protein; ER, endoplasmic reticulum; GRP78, 78 kDa glucose regulated protein/BiP; D-PSP, Dorosophia ortholog PSP.Article published online ahead of print. Article and publication date are at http://www.proteinscience.org/cgi
Lysosomes, isolated from rat liver after 70% partial hepatectomy (PHX), were found, by Western blotting, to contain a considerable amount of serum albumin. The level of intralysosomal serum albumin after PHX showed biphasic patterns: it increased immediately after PHX, peaked at 30 min, rapidly declined within a few hours, rose again with a peak at 15 hr, and gradually declined thereafter. At 15 hr after PHX, the content of lysosomal proteins in the liver increased to twice the level of unoperated control, and the electron-microscopic observation of the isolated lysosomes revealed numerous large membrane-delimited structures with ground substances of variable electron opacities. The increase in the intralysosomal serum albumin at 30 min and 15 hr was accompanied by changes in the buoyant densities of endosomes in Percoll density gradients. At both time points, the density profiles of endosomes isolated from hepatectomized rats shifted to the denser direction, suggesting that PHX activates fusion and/or maturation of endosomes. Formaldehyde-treated bovine serum albumin is known to be taken up by the liver by receptor-mediated endocytosis. The uptake of the modified heterologous albumin was shown to be activated as early as 30 min after PHX. Both the uptake of serum albumin into lysosomes and the shift of buoyant density profile of endosomes after PHX were inhibited by the administration of adrenergic receptor antagonists, particularly by the alpha r-antagonist prazosin. Further, the concentration of catecholamines in rat serum, particularly that of norepinephrine, was found to increase immediately after PHX, relative to that in serum from sham-operated rats. These results suggest that the elevation of serum norepinephrine levels after PHX activates endocytosis and facilitates delivery of endocytosed serum albumin to lysosomes, where albumin is digested to yield amino acids for possible use in protein synthesis during liver regeneration.
Objective: Various factors influence the manifestation of premenstrual symptoms (PMS). It has been associated with sleeping time, nutrition intake, absence of meal, exercise habits, leanness, and obesity. It is necessary to analyze their associations with PMS from a continuous and multifaceted perspective. We examined the relationship between premenstrual syndrome and dietary habits in women.Methods: Fifty-two college women completed questionnaires on menstrual syndrome, lifestyle, and food intakes. Menstrual symptoms were assessed using MDQ (Menstrual Distress Questionnaire).Spearman's rank correlation coefficients were used to examine the correlation between MDQ score and food intakes.Results: MDQ score correlated with intake of animal protein, animal fat, saturated fatty acid, saturated fatty acid energy ratio, cholesterol and carbohydrate. In term of food, MDQ score correlated with intake of meat, eggs, dairy products, cereal, and sugar. MDQ score was higher in people who did not intake certain combinations of food or did not use certain cooking methods. Conclusions:We found that intake of certain nutrients and foods were associated with premenstrual symptoms. Improvement of eating habits may be one way to relieve premenstrual symptoms.Jpn. J. Nutr. Diet., 77 (4) 77~84 (2019)
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