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51.
52.
Chemical investigation of endemic Algerian plant Launaea arborescens resulted in the isolation of a series of triterpenes and sesquiterpenes from both the aerial parts and roots. Five terpenoids have been chemically characterised by means of spectral methods mainly NMR techniques. In addition, the absolute stereochemistry at the chiral carbon in the side chain of 8-deoxy-15-(3′-hydroxy-2′-methyl-propanoyl)-lactucin-3′-sulfate (6) has been determined by comparison of the 1H NMR spectra of Mosher derivatives of 6 with those of the corresponding MTPA esters of model compounds. 相似文献
53.
Giuseppe Battaglia Milena Cannella Barbara Riozzi Sara Orobello Marion L. Maat‐Schieman Eleonora Aronica Carla Letizia Busceti Andrea Ciarmiello Silvia Alberti Enrico Amico Jenny Sassone Simonetta Sipione Valeria Bruno Luigi Frati Ferdinando Nicoletti Ferdinando Squitieri 《Journal of cellular and molecular medicine》2011,15(3):555-571
A defective expression or activity of neurotrophic factors, such as brain‐ and glial‐derived neurotrophic factors, contributes to neuronal damage in Huntington’s disease (HD). Here, we focused on transforming growth factor‐β (TGF‐β1), a pleiotropic cytokine with an established role in mechanisms of neuroprotection. Asymptomatic HD patients showed a reduction in TGF‐β1 levels in the peripheral blood, which was related to trinucleotide mutation length and glucose hypometabolism in the caudate nucleus. Immunohistochemical analysis in post‐mortem brain tissues showed that TGF‐β1 was reduced in cortical neurons of asymptomatic and symptomatic HD patients. Both YAC128 and R6/2 HD mutant mice showed a reduced expression of TGF‐β1 in the cerebral cortex, localized in neurons, but not in astrocytes. We examined the pharmacological regulation of TGF‐β1 formation in asymptomatic R6/2 mice, where blood TGF‐β1 levels were also reduced. In these R6/2 mice, both the mGlu2/3 metabotropic glutamate receptor agonist, LY379268, and riluzole failed to increase TGF‐β1 formation in the cerebral cortex and corpus striatum, suggesting that a defect in the regulation of TGF‐β1 production is associated with HD. Accordingly, reduced TGF‐β1 mRNA and protein levels were found in cultured astrocytes transfected with mutated exon 1 of the human huntingtin gene, and in striatal knock‐in cell lines expressing full‐length huntingtin with an expanded glutamine repeat. Taken together, our data suggest that serum TGF‐β1 levels are potential biomarkers of HD development during the asymptomatic phase of the disease, and raise the possibility that strategies aimed at rescuing TGF‐β1 levels in the brain may influence the progression of HD. 相似文献
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Raffaella Scardigli Silvia Soddu Rita Falcioni Marco Crescenzi Letizia Cimino Ada Sacchi 《Experimental cell research》1996,227(2):223
Integrin β4subunit is present in association with α6chain on both normal and transformed epithelial cells. Recently α6β4heterodimer was found on the endothelium of medium-sized blood vessels and on immature thymocytes. In this report we show, by Northern blotting, indirect immunofluorescence, immunoprecipitation, and Western blotting, that β4subunit is expressed also on cells of mesenchymal origin such as fibroblasts, myoblasts, and myotubes. Increased expression of α6β4has been related to the aggressive metastatic phenotype of human and murine carcinomas. The transforming growth factor β1(TGF-β1) has been found to modulate the expression of several integrins and intracellular matrix proteins, as well as to stimulate cell invasion and metastatic potential. To evaluate whether α6β4expression is modulated by TGF-β1, we transfected 3T3 fibroblasts with an expression vector carrying the human TGF-β1cDNA driven by the SV40 early promoter. We observed by indirect immunofluorescence a modification in the subcellular distribution of β4subunit, which acquires a perinuclear localization. This finding suggests this integrin subunit correlates with the cytoskeletal reorganization induced by TGF-β1. 相似文献
56.
The circadian rhythm of serum angiotensin-converting enzyme (ACE) activity was investigated in pregnant women with normal and pre-eclamptic gestation. The chronobiological approach was able to document the occurrence of a circadian rhythm for serum ACE activity in normal pregnancy. Such a rhythm is characterized by a decreased mesor and amplitude and a shifted crest. The circadian rhythm for serum ACE activity was not detectable in pre-eclamptic pregnancy. Such an abrogation is accompanied by a negligible decrease of mesor suggesting the occurrence of a relative hyperACEemia. This disorder could play a role in pregnancy-induced hypertension. 相似文献
57.
Letizia Mattii Francesco Bianchi Iana Da Prato Amelio Dolfi Nunzia Bernardini 《In vitro cellular & developmental biology. Animal》2001,37(4):251-258
Summary The present study was performed in four renal cell lines to evaluate their capability to: (1) produce and express transforming
growth factor α (TGFα), its respective receptor, the epidermal growth factor receptor (EGFr) and the small G protein, RhoA,
and (2) exhibit morphogenetic properties when grown on Matri-cell substrates. The cell lines were derived from normal (Madin-Darby
canine kidney cells), embryonic (SK-NEP-1 and 293 cells), and cancerous (human renal adenocarcinoma cells) kidneys. TGFα messenger
ribonucleic acid evaluated by a nonradioactive in situ hybridization technique, was found to be expressed in all the cell
lines. Large amounts of TGFα peptide were observed in all four cell lines, while EGFr was highly expressed only in cancerous
ACHN and embryonic-tumor SK-NEP-1 cells. RhoA peptide was found in appreciable amounts in SK-NEP-1 and 293 cells (compared
to the other two cell lines). The morphogenetic properties of the four cell lines were assessed, by culturing them on Matri-cell
dishes: SK-NEP-1 cells alone were found to grow in three-dimensional structures forming clusters and worm-like cellular aggregates.
This feature was displayed by SK-NEP-1 cells but not by the other three cell lines, and may be connected with the contemporary
presence of RhoA, EGFr, and TGFα found in significant amounts only in the SK-NEP-1 cell line. 相似文献
58.
Marie-Pierre Piccinni Letizia Lombardelli Federica Logiodice Ornela Kullolli Paola Parronchi Sergio Romagnani 《Clinical and molecular allergy : CMA》2016,14(1):11
Autoimmune disorders are characterized by tissue damage, caused by self-reactivity of different effectors mechanisms of the immune system, namely antibodies and T cells. Their occurrence may be associated with genetic and/or environmental predisposition and to some extent, have implications for fertility and obstetrics. The relationship between autoimmunity and reproduction is bidirectional. This review only addresses the impact of pregnancy on autoimmune diseases and not the influence of autoimmunity on pregnancy development. Th17/Th1-type cells are aggressive and pathogenic in many autoimmune disorders and inflammatory diseases. The immunology of pregnancy underlies the role of Th2-type cytokines to maintain the tolerance of the mother towards the fetal semi-allograft. Non-specific factors, including hormonal changes, favor a switch to Th2-type cytokine profile. In pregnancy Th2, Th17/Th2 and Treg cells accumulate in the decidua but may also be present in the mother’s circulation and can regulate autoimmune responses influencing the progression of autoimmune diseases. 相似文献
59.
Fumagalli M Daniele S Lecca D Lee PR Parravicini C Fields RD Rosa P Antonucci F Verderio C Trincavelli ML Bramanti P Martini C Abbracchio MP 《The Journal of biological chemistry》2011,286(12):10593-10604
The developing and mature central nervous system contains neural precursor cells expressing the proteoglycan NG2. Some of these cells continuously differentiate to myelin-forming oligodendrocytes; knowledge of the destiny of NG2(+) precursors would benefit from the characterization of new key functional players. In this respect, the G protein-coupled membrane receptor GPR17 has recently emerged as a new timer of oligodendrogliogenesis. Here, we used purified oligodendrocyte precursor cells (OPCs) to fully define the immunophenotype of the GPR17-expressing cells during OPC differentiation, unveil its native signaling pathway, and assess the functional consequences of GPR17 activation by its putative endogenous ligands, uracil nucleotides and cysteinyl leukotrienes (cysLTs). GPR17 presence was restricted to very early differentiation stages and completely segregated from that of mature myelin. Specifically, GPR17 decorated two subsets of slowly proliferating NG2(+) OPCs: (i) morphologically immature cells expressing other early proteins like Olig2 and PDGF receptor-α, and (ii) ramified preoligodendrocytes already expressing more mature factors, like O4 and O1. Thus, GPR17 is a new marker of these transition stages. In OPCs, GPR17 activation by either uracil nucleotides or cysLTs resulted in potent inhibition of intracellular cAMP formation. This effect was counteracted by GPR17 antagonists and receptor silencing with siRNAs. Finally, uracil nucleotides promoted and GPR17 inhibition, by either antagonists or siRNAs, impaired the normal program of OPC differentiation. These data have implications for the in vivo behavior of NG2(+) OPCs and point to uracil nucleotides and cysLTs as main extrinsic local regulators of these cells under physiological conditions and during myelin repair. 相似文献
60.