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Expression of adult fast pattern of acetylcholinesterase molecular forms by mouse satellite cells in culture 总被引:1,自引:0,他引:1
M. Immacolata Senni Francesco Castrignanò Giancarlo Poiana Giulio Cossu Gianfranco Scarsella Stefano Biagioni 《Differentiation; research in biological diversity》1987,36(3):194-198
The pattern of acetylcholinesterase (AChE) molecular forms, obtained by sucrose gradient sedimentation, was studied at different in vitro developmental stages of myogenic cells isolated from adult mouse skeletal muscle. Only the globular forms were present in rapidly dividing satellite cells during the first days in culture. After myotube formation, a pattern similar to that described in mammalian fast-twitch skeletal muscle was observed. This pattern did not change during the following period in culture (up to 1 month) nor could it be modified by co-culturing with spinal cord motoneurons or by addition of brain-derived extracts. The internal-external localization of AChE molecular forms has been determined by the use of echothiophate iodide, a membrane-impermeant irreversible inhibitor of AChE. Echothiophate-treated cultures showed about 40% of both asymmetric and globular forms localized on the sarcolemma, with their active sites oriented outward. Analysis of culture medium from untreated cultures revealed the presence of both asymmetric and globular forms. When the same analysis was repeated on cultures of myoblasts derived from 16-day-old mouse embryos, the pattern of AChE forms was different. The myotubes derived from these cells exhibit a very small proportion of asymmetric form, which was not released into the medium. This pattern was not further modified during the following days of culture, nor by co-cultures with spinal cord motoneurons or by incubations with brain-derived extracts. Thus, the myotubes derived from myoblasts express in culture a clear phenotypic difference when compared to the corresponding myotubes from satellite cells, supporting the view that these two myogenic cells are endowed with different developmental programs. 相似文献
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Giuliana Catara Immacolata Fiume Filippo Iuliano Giovanna Maria Giuseppe Ruggiero 《Biocatalysis and Biotransformation》2013,31(5):358-370
A new serine-carboxyl proteinase, called kumamolisin-ac, was purified from the thermoacidophilic bacterium Alicyclobacillus acidocaldarius. The enzyme is a monomeric protein of 45?kDa, active over a wide temperature range (5.0–70°C) and extremely acidic pHs (1.0–4.0), showing maximal proteolytic activity at pH?2.0 and 60°C. Interestingly, kumamolisin-ac displayed a significant proteolytic activity even at 5°C, thus suggesting a sort of cold-adaptation for this enzyme. The protease was remarkably stable at high temperatures (t1/2 at 80°C, 10?h, pH?2.0) and over a broad range of pH (2.0–7.0). Substrate analysis indicated that kumamolisin-ac was active on a variety of macromolecular substrates, such as haemoglobin, hide powder azure, and azocoll. In particular, a high specific activity was detected towards collagen. The corresponding gene was cloned, expressed and the recombinant protease, was found to be homologous to proteases of the ‘S53’ family. From the high identity with kumamolisin and kumamolisin-As, known as collagenolytic proteases, kumamolisin-ac can be considered as the third collagenolytic affiliate within the ‘S53’ family. Cleavage specificity investigation of kumamolisin-ac revealed a unique primary cleavage site in bovine insulin B-chain, whereas a broad specificity was detected using bovine α-globin as substrate. Thus, kumamolisin-ac could represent an attractive candidate for industrial-scale biopeptide production under thermoacidophilic conditions. 相似文献
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Messi Patrizia Bargellini Annalisa Anacarso Immacolata Marchesi Isabella Simona de Niederhäusern Bondi Moreno 《Archives of microbiology》2013,195(2):89-96
Three Legionella pneumophila strains isolated from municipal hot tap water during a multicentric Italian survey and belonging to serogroups 1, 6, 9 and the reference strain Philadelphia-1 were studied to determine the intracellular replication capability and the cytopathogenicity in human monocyte cell line U937 and in an Acanthamoeba polyphaga strain. Our results show that both serogroups 1 and Philadelphia-1 were able to multiply into macrophages inducing cytopathogenicity, while serogroup 6 and ever more serogroup 9 were less efficient in leading to death of the infected macrophages. Both serogroups 1 and 6 displayed a quite good capability of intracellular replication in A. polyphaga, although serogroup 1 was less cytopathogenic than serogroup 6. Serogroup 9, like Philadelphia-1 strain, showed a reduced efficiency of infection and replication and a low cytopathogenicity towards the protozoan. Our study suggests that bacterial pathogenesis is linked to the difference in the virulence expression of L. pneumophila serogroups in both hosts, as demonstrated by the fact that only L. pneumophila serogroup 1 shows the contextual expression of the two virulence traits. Serogroup 6 proves to be a good candidate as pathogen since it shows a good capacity for intracellular replication in protozoan. 相似文献
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Ana S. Luís Immacolata Venditto Max J. Temple Artur Rogowski Arnaud Baslé Jie Xue J. Paul Knox José A.M. Prates Luís M. A. Ferreira Carlos M. G. A. Fontes Shabir Najmudin Harry J. Gilbert 《The Journal of biological chemistry》2013,288(7):4799-4809
Plant biomass is central to the carbon cycle and to environmentally sustainable industries exemplified by the biofuel sector. Plant cell wall degrading enzymes generally contain noncatalytic carbohydrate binding modules (CBMs) that fulfil a targeting function, which enhances catalysis. CBMs that bind β-glucan chains often display broad specificity recognizing β1,4-glucans (cellulose), β1,3-β1,4-mixed linked glucans and xyloglucan, a β1,4-glucan decorated with α1,6-xylose residues, by targeting structures common to the three polysaccharides. Thus, CBMs that recognize xyloglucan target the β1,4-glucan backbone and only accommodate the xylose decorations. Here we show that two closely related CBMs, CBM65A and CBM65B, derived from EcCel5A, a Eubacterium cellulosolvens endoglucanase, bind to a range of β-glucans but, uniquely, display significant preference for xyloglucan. The structures of the two CBMs reveal a β-sandwich fold. The ligand binding site comprises the β-sheet that forms the concave surface of the proteins. Binding to the backbone chains of β-glucans is mediated primarily by five aromatic residues that also make hydrophobic interactions with the xylose side chains of xyloglucan, conferring the distinctive specificity of the CBMs for the decorated polysaccharide. Significantly, and in contrast to other CBMs that recognize β-glucans, CBM65A utilizes different polar residues to bind cellulose and mixed linked glucans. Thus, Gln106 is central to cellulose recognition, but is not required for binding to mixed linked glucans. This report reveals the mechanism by which β-glucan-specific CBMs can distinguish between linear and mixed linked glucans, and show how these CBMs can exploit an extensive hydrophobic platform to target the side chains of decorated β-glucans. 相似文献
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Eleonora Scalco Alberto Amato Maria Immacolata Ferrante Marina Montresor 《Protoplasma》2016,253(6):1421-1431
Pseudo-nitzschia is a thoroughly studied pennate diatom genus for ecological and biological reasons. Many species in this genus, including Pseudo-nitzschia multistriata, can produce domoic acid, a toxin responsible for amnesic shellfish poisoning. Physiological, phylogenetic and biological features of P. multistriata were studied extensively in the past. Life cycle stages, including the sexual phase, fundamental in diatoms to restore the maximum cell size and avoid miniaturization to death, have been well described for this species. P. multistriata is heterothallic; sexual reproduction is induced when strains of opposite mating type are mixed, and proceeds with cells producing two functionally anisogamous gametes each; however, detailed cytological information for this process is missing. By means of confocal laser scanning microscopy and nuclear staining, we followed the nuclear fate during meiosis, and using time-lapse cinematography, we timed every step of the sexual reproduction process from mate pairing to initial cell hatching. The present paper depicts cytological aspects during gametogenesis in P. multistriata, shedding light on the chloroplast behaviour during sexual reproduction, finely describing the timing of the sexual phases and providing reference data for further studies on the molecular control of this fundamental process. 相似文献
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Cecilia Nigro Alessia Leone Michele Longo Immacolata Prevenzano Thomas H. Fleming Antonella Nicolò Luca Parrillo Rosa Spinelli Pietro Formisano Peter P. Nawroth Francesco Beguinot Claudia Miele 《生物化学与生物物理学报:疾病的分子基础》2019,1865(1):73-85
Impaired angiogenesis leads to long-term complications and is a major contributor of the high morbidity in patients with Diabetes Mellitus (DM). Methylglyoxal (MGO) is a glycolysis byproduct that accumulates in DM and is detoxified by the Glyoxalase 1 (Glo1). Several studies suggest that MGO contributes to vascular complications through mechanisms that remain to be elucidated. In this study we have clarified for the first time the molecular mechanism involved in the impairment of angiogenesis induced by MGO accumulation.Angiogenesis was evaluated in mouse aortic endothelial cells isolated from Glo1-knockdown mice (Glo1KD MAECs) and their wild-type littermates (WT MAECs). Reduction in Glo1 expression led to an accumulation of MGO and MGO-modified proteins and impaired angiogenesis of Glo1KD MAECs. Both mRNA and protein levels of the anti-angiogenic HoxA5 gene were increased in Glo1KD MAECs and its silencing improved both their migration and invasion. Nuclear NF-?B-p65 was increased 2.5-fold in the Glo1KD as compared to WT MAECs. Interestingly, NF-?B-p65 binding to HoxA5 promoter was also 2-fold higher in Glo1KD MAECs and positively regulated HoxA5 expression in MAECs. Consistent with these data, both the exposure to a chemical inhibitor of Glo1 “SpBrBzGSHCp2” (GI) and to exogenous MGO led to the impairment of migration and the increase of HoxA5 mRNA and NF-?B-p65 protein levels in microvascular mouse coronary endothelial cells (MCECs).This study demonstrates, for the first time, that MGO accumulation increases the antiangiogenic factor HoxA5 via NF-?B-p65, thereby impairing the angiogenic ability of endothelial cells. 相似文献
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Villa I Dal Fiume C Maestroni A Rubinacci A Ravasi F Guidobono F 《American journal of physiology. Endocrinology and metabolism》2003,284(3):E627-E633
The calcitonin peptides [calcitonin (CT), calcitonin gene-related peptide (CGRP), amylin] share many biological actions, including activity on bone cells. In the present study, CT (10(-11) to 10(-9) M) stimulated [(3)H]thymidine incorporation in primary cultures of human osteoblasts (hOB), as already demonstrated for CGRP and amylin. RT-PCR analysis showed that the calcitonin receptor and the calcitonin receptor-like receptor are both expressed in hOB. In these cells, CT (10(-10) M) and amylin (10(-9) M), in contrast to CGRP (10(-8) M), did not increase cAMP production. All three peptides stimulated protein kinase C (PKC) activity. To evaluate PKC involvement in hOB proliferation, cells were incubated with phorbol 12,13-dibutyrate, a stimulator of PKC activity; cell proliferation was increased in a dose-dependent manner (EC(50) = 3.4 x 10(-8) M). Staurosporine (10(-9) M), a PKC inhibitor, blocked phorbol 12,13-dibutyrate-induced PKC activity and cell proliferation. Inhibition of PKC by staurosporine also counteracted the stimulatory effect of CT, CGRP, and amylin on hOB proliferation. From these data, it is deduced that the activation of PKC is important for hOB proliferation and that it is involved in the anabolic effect of CT peptides on bone. 相似文献