Peptidal Sex Hormones Inducing Conjugation Tube Formation in Compatible Mating-Type Cells of Tremella mesenterica.

The pair of peptidal sex hormones (tremerogen A-10 and tremerogen a-13) that induce conjugation tube formation in compatible type cells (A and a types) of Tremella mesenterica were isolated. Tremerogen A-10 is a dodecapeptide and tremerogen a-13, a tridecapeptide. In both peptides, the sulfiydryl group of the cysteines at the carboxyl terminus was blocked by farnesyl moieties.

Isolation and structure of bacterial sex pheromone, cPD1.

The Streptococcus faecalis sex pheromone cPD1, which induces a mating response in cells harboring the conjugative plasmid pPD1, has been isolated and its structure determined. It was found to have a molecular weight of 912, and its amino acid sequence was H-Phe-Leu-Val-Met-Phe-Leu-Ser-Gly-OH. A synthetic octapeptide showed the same biological activity and chromatographic behavior as the isolated cPD1. Pheromone activity was detectable at a concentration of approximately 4 X 10(-11)M.

Accelerated mammary cancer development by fetal salivary mesenchyma isografted to adult mouse mammary epithelium.

Transplantation of fetal salivary mesenchyma into adult mammary glands resulted in atypical outgrowths from the mammary duct system. These duct-alveolus nodules (DAN) were distinguishable from hyperplastic alveolar nodules (HAN) that arose from normal mammary duct systems in mice infected with murine mammary tumor virus (MuMTV). DAN displayed a type of ductal branching characteristic of salivary gland rather than of mammary gland, reflecting a tissue-specific perturbation of epithelium-mesenchyma in DAN in milk-transmitted MuMTV-infected C3H/HeN mice and in MuMTV-negative BALB/c mice given 7,12-dimethylbenz[a]anthracene (DMBA) subsequent to transplantation of fetal salivary mesenchyma. Mammary cancers were not increased in milk-transmitted MuMTV-free C3H/HeN and GRS/A mice that received salivary mesenchyma transplants. Salivary mesenchyma accelerated mammary carcinogenesis by increasing the mammary epithelial cell population responsive to MuMTV and DMBA.

Peptide signals and their receptors in higher plants.

At least four peptides play a vital role in plant cell-cell communication by means of their specific receptors. Two of these receptors have been identified as receptor kinases, which form a large family of receptor molecules in plants. These findings highlight the significance of receptor-mediated peptide signaling in various physiological events in plants, and predict the existence of further peptide-signal-interacting receptor kinases. Some candidates have been found in plant genomes. Here, we outline recent progress and future challenges in the signaling peptide analysis, which began with systemin, phytosulfokine, CLAVATA3 and S-locus cysteine-rich protein (also called S-locus protein 11).

Effects of retinoids on induction of differentiation of cultured mouse myeloid leukemia cells.

Retinoic acid, retinol, retinyl acetate, and retinal induced activities of lysosomal enzymes, such as lysozyme, acid protease, and acid phosphatase, in mouse myeloid leukemia cells (M1), while the pyridyl analog of retinoic acid had no effect. Retinoic acid was the most potent inducer of lysosomal enzyme activities. The induction of lysozyme activity by retinoic acid was inhibited by treatment with puromycin. The retinoids did not induce phagocytic and locomotive activities or morphological changes in M1 cells, and they inhibited the induction of these differentiation-associated properties by various inducers without inhibiting cell growth. Retinoic acid was the most potent inhibitor of induction of these differentiation-associated properties. The inhibitory effect of retinoic acid was found to be reversible. These results suggest that distinct mechanisms exist for control of induction of lysosomal enzyme activities and of other differentiation-associated properties of M1 cells, such as phagocytosis, morphological changes, and migration.

Intestine-like remodeling of adult mouse glandular stomach by implanting of fetal intestinal mesenchyme.

A morphogenetic response of adult glandular stomach grown in contact with implanted fetal intestinal mesenchyme has been demonstrated. Mesenchymal tissues from intestines of 14- to 16-day-old BALB/c mouse fetuses were introduced beneath the epithelial layer of glandular stomach in 2-month-old mice and allowed to develop. Three to 4 weeks later, remodeling of the epithelial architecture had occurred; the characteristic glandular pit structure of normal stomach had been replaced by immature villi and crypts composed of mucus-secreting columnar cells more characteristic of intestinal tissues. Chief and parietal cells had disappeared, but neither goblet nor Paneth cells were observed. Such intestine-like morphogenesis was not induced by similarly implanted mesenchymal controls from fetal glandular stomach, forestomach, and salivary gland. A possible role of the mesenchymal stroma in the pathogenesis of intestinal metaplasia in stomach is discussed.

The endogenous sulfated pentapeptide phytosulfokine-alpha stimulates tracheary element differentiation of isolated mesophyll cells of zinnia

Dispersed zinnia (Zinnia elegans) mesophyll cells cannot differentiate into tracheary elements (TEs) at low cell density conditions even if auxin and cytokinin are present in the medium, indicating the involvement of intercellular interactions during the initiation and/or subsequent progresses in TE differentiation. When zinnia cells were incubated at a low density (2.5 x 10(4) cells mL(-1)) in TE-inductive medium in the presence of various concentrations of phytosulfokine (PSK)-alpha, which was originally identified as an intercellular signal peptide involved in cell proliferation, TE differentiation was strongly stimulated in a dose-dependent fashion; more than 35% of the living cells differentiated into TEs by 5 d of culture in the presence of 10 nM PSK-alpha. Enzyme-linked immunosorbent assay and mass spectroscopy confirmed that cultured zinnia cells produce nanomolar levels of PSKs under inductive conditions. These results suggest that PSK-alpha is a factor responsible for TE differentiation of zinnia mesophyll cells.

Stimulation of interleukin-6 production by either calcitonin gene-related peptide or parathyroid hormone in two phenotypically distinct bone marrow-derived murine stromal cell lines.

It was recently shown that interleukin-6 (IL-6) is produced by bone and bone marrow-derived stromal cells and that it plays an important role in osteoclast development. Here we examined whether parathyroid hormone (PTH), calcitonin (CT), or the calcitonin gene-related peptide (CGRP) influence IL-6 production by two murine bone marrow-derived stromal cell lines: the preadipocyte-like stromal cell line +/+ LDA11 and the fibroendothelial stromal cell line MBA 13.2. We found that CGRP (but not PTH or CT) exerted a dose-dependent increase in cAMP and IL-6 production in the +/+ LDA11 cells. In addition, CGRP had an inhibiting effect on the proliferation of this stromal cell line. CGRP, however, did not affect cAMP or IL-6 in the rat osteogenic sarcoma cell line UMR-106-06, which exhibits CT receptors, whereas CT stimulated both cAMP and IL-6 by the UMR-106-01 cells. In contrast to the specificity of the IL-6 response of the +/+ LDA11 cells to CGRP, IL-6 production by the MBA 13.2 stromal cells was stimulated by PTH whereas CGRP or CT had no effect. These data suggest that bone marrow-derived stromal cells express receptors for either CGRP or PTH in a phenotype-specific manner and that, acting via these receptors, CGRP and PTH stimulate IL-6 production by stromal cells. In addition, the evidence for specific receptors for the neuropeptide CGRP in bone marrow stromal cells and an effect of CGRP on IL-6 raises the possibility for a role of cytokines in a putative interplay between neuronal stimuli and bone.

Cytokine production and surface antigen expression by peripheral blood mononuclear cells in postmenopausal osteoporosis.

It was reported earlier that IL-1 production by cultured monocytes and the ratio of helper (CD4) to suppressor (CD8) lymphocytes in peripheral blood are different in osteoporotic compared to nonosteoporotic subjects. We examined these and several other parameters related to the biosynthetic activity and differentiation status of peripheral blood mononuclear cells (PBMC) in untreated osteoporotic postmenopausal women (age 65 +/- 7, n = 46), nonosteoporotic postmenopausal women (age 55 +/- 3, n = 20), and nonosteoporotic premenopausal women (age 37 +/- 7, n = 8), as defined by spine density. We found that unstimulated monocytes from osteoporotics did not produce detectable IL-1 beta as determined by ELISA. In addition, there were no significant differences between osteoporotics and nonosteoporotics in IL-1 beta or IFN-gamma production by PBMC stimulated with OKT3, a monoclonal antibody to the T cell-receptor complex. The proliferative response of lymphocytes to OKT3 was significantly less (p < 0.02) in osteoporotics compared to nonosteoporotic post- and premenopausal women; multiple-regression analysis, however, indicated that this difference was not due to bone density but to age. Flow cytometric analysis of PBMC revealed no difference between osteoporotics and nonosteoporotics in the distribution of 18 phenotypic subsets determined, including CD4- or CD8-positive lymphocytes or the ratio of CD4 to CD8 cells. Further, there was no correlation of the surface markers with bone density, the exceptions being the subsets expressing the CD3/CD56 and CD8/CD56 markers, which were inversely related to spine density in the osteoporotic women.(ABSTRACT TRUNCATED AT 250 WORDS)

Distinct target cells and effects of 1 alpha,25-dihydroxyvitamin D3 and glucocorticoids in the rat thymus gland.

Thymocytes are known to possess receptors for glucocorticoids (GC) as well as for alpha, 25-dihydroxyvitamin D3 [1,25-(OH)2D3]. We have now investigated the distribution of the receptors for GC and 1,25-(OH)2D3 in rat thymocytes and compared the effects of the two steroid hormones on short term primary cultures of these cells. We report that in thymic cells, as in other tissues, 1,25-(OH)2D3 and GC bind specifically to distinct receptor molecules which exhibit sedimentation coefficients of 3.3S and 3.7S, respectively. Furthermore, the thymocytes that express the 1,25-(OH)2D3 receptor belong to a different and distinct subpopulation than the cells that express the glucocorticoid receptor. Specifically, by separating the thymocytes into two subsets by means of agglutination with the lectin peanut agglutinin (PNA), we have determined that the 1,25-(OH)2D3 receptor-positive cells belong to the PNA-negative medullary mature subset, whereas the GC receptor-positive cells belong to the PNA-positive cortical immature subset of thymocytes. Finally, we have compared the effects of the two steroid hormones on primary cultures of each of the two subsets as well as on unseparated thymocytes and found that GC act on PNA-positive cells to induce cell lysis; this leads to an enrichment in 1,25-(OH)2D3 receptor-positive thymocytes, as indicated by an apparent increase (6-fold) in the 1,25-(OH)2D3 binding in the cells surviving at the end of the culture. In contrast, we found that 1,25-(OH)2D3 acts on the PNA-negative cells to decrease the rate of cell lysis. These data indicates that the target cells for GC and 1,25-(OH)2D3 in the thymus are distinct and that these two hormones exert a different regulatory influence on the gland.

Existence of a plant tyrosylprotein sulfotransferase: novel plant enzyme catalyzing tyrosine O-sulfation of preprophytosulfokine variants in vitro.

An in vitro assay system to detect tyrosylprotein sulfotransferase (TPST) activity of higher plant cells was established, using synthetic oligopeptides based on the deduced amino acid sequence of a phytosulfokine-alpha (PSK-alpha) precursor. TPST activity was found in microsomal membrane fractions of rice, asparagus and carrot cells and it was confirmed that acidic amino acid residues adjacent to the tyrosine residues of acceptor peptides were essential to the sulfation reaction. The asparagus TPST exhibited a broad pH optimum of 7.0-8.5, required manganese ions for maximal activity and appeared to be a membrane-bound protein localized in the Golgi apparatus. These enzymes should be defined as a new class of plant sulfotransferases that catalyze tyrosine O-sulfation of a PSK-alpha precursor and other unknown proteins.

Isolation and structure of the bacterial sex pheromone, cAD1, that induces plasmid transfer in Streptococcus faecalis.

The Streptococcus faecalis sex pheromone cAD1, which is involved in the conjugative transfer of the hemolysin plasmid pAD1, has been isolated and its structure determined. Its Mr is 818 and its amino acid sequence is H-Leu-Phe-Ser-Leu-Val-Leu-Ala-Gly-OH. A replicate of the pheromone synthesized by the liquid-phase method showed the same biological activity and chromatographic behavior as the isolated cAD1. Pheromone activity was detectable at a concentration of approximately 5 X 10(-11) M.

Isolation and structure of the Streptococcus faecalis sex pheromone, cAM373.

The Streptococcus faecalis sex pheromone, cAM373, which induces a mating response of donor cells harboring plasmid pAM373 and is also produced by Staphylococcus aureus, was isolated and its structure determined. Supernatant from an overnight culture of a recipient strain was subjected to successive purification procedures, and 4.4 micrograms cAM373 was obtained. The isolated pheromone showed activity at a concentration as low as 5 X 10(-11) M. Sequence analysis indicated that cAM373 was a heptapeptide, H-Ala-Ile-Phe-Ile-Leu-Ala-Ser-OH, and that its Mr was 733. A synthetic replicate of the peptide showed the same biological activity and chromatographic behavior as the native cAM373.

Effect of ageing on erythrocyte aldose reductase and sorbitol dehydrogenase activity.

We measured erythrocyte aldose reductase and sorbitol dehydrogenase activity in erythrocytes in healthy individuals aged from 16 to 91 years to determine the mechanism of age-dependent sorbitol accumulation. Erythrocyte aldose reductase activity increased significantly with age but ageing had no effect on sorbitol dehydrogenase activity. Age and the aldose reductase/sorbitol dehydrogenase ratio were positively correlated. These findings suggest that an increase in the ratio of aldose reductase to sorbitol dehydrogenase may contribute to the tissue accumulation of sorbitol in the elderly and may be a mechanism of a disease that is common in elderly individuals.

Bone changes and aortic calcification in aging inhabitants of mountain versus seacoast communities in the Kii Peninsula.

Bone changes and aortic calcification were compared radiographically for different age groups of the inhabitants of two communities on the Kii Peninsula at the central southern tip of the Japanese mainland, one a mountainous Shichikawa village with a traditionally restricted nutritional intake and the other a seacoast village on Oshima Island with an abundant nutritional supply. Changes in the physical properties of the bone were also assessed by resonance measurement. In the mountainous village, bone loss appeared to occur more rapidly than in the seacoast village, as indicated by a significantly higher frequency of thoracic vertebral deformity and more pronounced age-bound decrease of ulnar resonant frequency. Aortic calcification was also more frequent in Shichikawa than on Oshima Island. Such differences were more evident in women than in men. The poorer nutritional intake (especially of calcium and vitamin D) of persons living in the mountainous village (which receives less sunshine) might be responsible for the accelerated age-bound degenerative changes observed in their skeletal and vascular systems.

Calcium metabolism in aging inhabitants of mountain versus seacoast communities in the Kii Peninsula.

A survey was conducted on age-related changes in various measures of calcium metabolism in 609 men and women over the age of 30 (more than half were over the age of 60) in two communities of the Kii Peninsula at the central southern tip of the Japanese mainland. One community was on Oshima Island, with adequate nutritional intake; the other community was in the mountainous Shichikawa district, with a low intake of calcium and protein. The subjects of the Shichikawa study showed shorter stature, higher prevalence of lumbago, thinner clavicular cortex, lower serum levels of phosphorus, total protein and cholesterol, and a higher level of alkaline phosphatase than did the subjects of the Oshima study. There was no difference in the serum calcium levels.

Release of leukotriene B4 from rat Kupffer cells.

In order to examine the production of leukotriene B4 (LTB4) from Kupffer cells, Kupffer cells isolated from the normal rat liver were incubated with calcium ionophore A23187, opsonized zymosan, or platelet activating factor (PAF), and the amount of LTB4 in the culture supernatant was determined by the combined technique of reverse-phase high-performance liquid chromatography and radioimmunoassay. As a result, when activated in vitro with calcium ionophore A23187, Kupffer cells generated LTB4. When Kupffer cells were stimulated with calcium ionophore after 10-min preincubation with AA861, a selective 5-lipoxygenase inhibitor, the release of LTB4 from Kupffer cells was markedly suppressed. PAF, which is a phospholipid mediator having a wide spectrum of biological activities, significantly enhanced the release of LTB4 from Kupffer cells stimulated with calcium ionophore or opsonized zymosan. Even when the Kupffer cell were not stimulated with calcium ionophore or opsonized zymosan, LTB4 production was significantly increased by PAF. Thus, our studies indicate that Kupffer cells could generate LTB4 as well as polymorphonuclear leukocytes and macrophages. In addition, it is suggested that Kupffer cells may be able to modify inflammatory and immunological events in the liver tissue by the release of LTB4.

Changes in leukotrienes and prostaglandins in the liver tissue of rats in the experimental massive hepatic cell necrosis model.

When heat-killed Propionibacterium acnes is intravenously injected into rats followed by an intravenous injection of a small amount of Gram-negative lipopolysaccharide (LPS) 7 days later, massive hepatic cell necrosis is induced and most of the rats die within 24 hours of LPS injection. Using this experimental model, we studied the changes in the levels of leukotrienes (LTs) and prostaglandins (PGs) in the liver tissue and bile of rats with experimentally-induced massive hepatic cell necrosis. Both the levels of LTs and PGs in the liver tissue and LTs in the bile increased before the microscopic appearance of hepatic cell necrosis. These results suggest that arachidonic acid metabolites may play an important role in the induction of liver cell injury.

Bactericidal activities of disinfectants against vancomycin-resistant enterococci.

The bactericidal activities of 35 commercially available disinfectants against vancomycin-resistant enterococci (VRE) and vancomycin-sensitive enterococci (VSE) were investigated under both clean and dirty (albumin added) conditions using a microtitration plate method. No differences in bactericidal time were observed with any of the test disinfectants when comparing activity against VRE or VSE. Isopropyl alcohol (70 v/v%), alcohol-containing preparations such as Welpas, Wellup and Maskin W . ethanol solution, 0.2% of cation surfactant disinfectants such as Osvan solution 'daigo', Germitol 'Maruishi' 10% and Hyamine solution, and 0.5% of amphoteric compound disinfectants such as TEGO-51, Hygieel and Hypal No.3, were the most effective compounds when compared with other disinfectants. These results suggest that the use of a disinfectant with activity against VRE may be one appropriate method for preventing infections caused by this micro-organism.

Eleven aristolochic acid derivatives from Aristolochia cinnabarina.

Three new compounds, aristolochic acid IIIa-6-O-beta-D-glucoside, cepharanone-A N-beta-D-glucoside and 2-hydroxy-8-methyloxycepharanone-A, were isolated together with eight known compounds from methanolic extracts of fresh roots of Aristolochia cinnabarina.