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1.
J Am Coll Health ; : 1-4, 2023 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-37053574

RESUMO

Background: Given the body image and disordered eating struggles prevalent in young adults, weight-inclusive anti-diet programs are needed on college campuses. Such programs replace weight loss advice with changes that center physical and mental well-being. Methods/Program Design: University health and wellness programs such as University Coaching for Activity and Nutrition (UCAN) is a novel weight-inclusive health and wellness coaching program designed to support university students and faculty/staff in their development and maintenance of self-care behaviors related to physical activity, nutrition, sleep, and stress management. Specifically, we describe the program's mechanisms for participant recruitment, health coach training, session protocol, program evaluation, and supervision so other campuses can replicate the program model at their respective universities. Discussion: This work can help campuses cultivate positive self-care habits that improve physical and mental health through the lens of a weight-inclusive paradigm while also creating research and service-learning experiences for pre-health professionals.

2.
Andrology ; 5(2): 256-261, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-28178400

RESUMO

Nitric oxide is a physiologic signal essential to penile erection. l-citrulline (l-Cit) is converted into l-arginine (l-Arg), the precursor from which nitric oxide is generated. The level of l-Arg and l-Cit in the field of male sexual function remains relatively underexplored. The aim of the study was to evaluate the level of serum l-Arg and of l-Cit in a group of patients with erectile dysfunction. Diagnosis and severity of erectile dysfunction was based on the IIEF-5 and its etiology was classified as arteriogenic (A-ED), borderline (BL-ED), and non-arteriogenic (NA-ED) with penile echo-color-Doppler in basal condition and after intracaversous injection of prostaglandin E1. Serum l-Arg and l-Cit concentrations were measured by a cation-exchange chromatography system. l-Arg and l-Cit levels of men with A-ED were compared with those of male with BL-ED and NA-ED. Median level of l-Arg and l-Cit in 122 erectile dysfunction patients (41 A-ED, 23 ED-BL, 58 NA-ED) was 82.7 and 35.4 µmol/L, respectively. l-Arg and l-Cit levels in control patients were not significantly different (p = 0.233 and p = 0.561, respectively) than in total erectile dysfunction patients. l-Arg and l-Cit levels in control patients were significantly higher (p < 0.001 and p < 0.018, respectively) than in A-ED patients, but no difference (p > 0.50) was observed in controls and in both BL-ED and NA-ED patients. Patients with severe/complete-erectile dysfunction (IIEF-5 < 10) had l-Arg or l-Cit level significantly lower (-17%, p < 0.03; -13%, p < 0.04) and were more frequent (p < 0.01 and p < 0.04) under the respective median level (82.7 and 35.4 µmol/L) than those with mild-erectile dysfunction (IIEF-5 = 16-20). l-Arg and l-Cit levels in A-ED were significantly lower (p < 0.007 and p < 0.001, respectively) than in NA-ED patients. Penile echo-color-Doppler revealed that A-ED (peak systolic velocity ≤ 25 cm/sec) was more frequent in men with l-Arg under 82.7 µmol/L or l-Cit under 35.4 µmol/L and in the same population, the median peak systolic velocity values were lower in l-Arg deficient (29 vs. 35; p < 0.04) and also in l-Cit deficient (31 vs. 33, p > 0.3) but without reaching the statistical significance. Our study shows that a significant proportion of erectile dysfunction patients have low l-Arg or l-Cit level and that this condition is more frequent in patients with arteriogenic etiology. Low levels of these nitric oxide synthase substrates might increase the erectile dysfunction risk by reducing the concentration of nitric oxide.


Assuntos
Arginina/sangue , Citrulina/sangue , Disfunção Erétil/sangue , Ereção Peniana/fisiologia , Adulto , Disfunção Erétil/diagnóstico por imagem , Disfunção Erétil/etiologia , Humanos , Masculino , Pessoa de Meia-Idade , Índice de Gravidade de Doença , Ultrassonografia Doppler em Cores
3.
Medchemcomm ; 8(7): 1505-1513, 2017 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-30108862

RESUMO

Newcastle Disease Virus (NDV), belonging to the Paramyxoviridae family, causes a serious infectious disease in birds, resulting in severe losses in the poultry industry every year. Haemagglutinin neuraminidase glycoprotein (HN) has been recognized as a key protein in the viral infection mechanism, and its inhibition represents an attractive target for the development of new drugs based on sialic acid glycals, with the 2-deoxy-2,3-didehydro-d-N-acetylneuraminic acid (Neu5Ac2en) as their backbone. Herein we report the synthesis of several Neu5Ac2en glycals and of their perfluorinated C-5 modified derivatives, including their respective stereoisomers at C-4, together with evaluation of their in vitro antiviral activity. While all synthesized compounds were found to be active HN inhibitors in the micromolar range, we found that their potency was influenced by the chain-length of the C-5 perfluorinated acetamido functionality. Thus, the binding modes of the inhibitors were also investigated by performing a docking study. Moreover, the perfluorinated glycals were found to be more active than the corresponding normal C-5 acylic derivatives. Finally, cell-cell fusion assays on NDV infected cells revealed that the addition of a newly synthesized C-4α heptafluorobutyryl derivative almost completely inhibited NDV-induced syncytium formation.

4.
Neurochem Int ; 40(3): 255-60, 2002 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11741009

RESUMO

Hypoxia-hypoglycemia has played an important role in inducing both phospholipase A2 activation and the expression of the early gene c-fos, in the neuroblastoma cell line SK-N-BE, after it has been differentiated by retinoic acid. Under hypoxic-hypoglycemic conditions, arachidonic acid release has found to be significant after 30 min, whereas c-fos expression has required at least 4 h. This model has been obtained by adding glycolytic inhibitor 2-deoxyglucose to the culture and by placing cells in an atmosphere containing 100% N2 for different time periods. This condition has been compared with two different models: NaCN and nitrogen have been used as hypoxic stimuli, without inhibiting the glycolytic pathway, but the same cell cultures have been used. Cell viability and the fall of cellular ATP levels have been evaluated in all the models, in order to monitor and compare the hypoxic cellular damage. Phospholipase A2 activation has been found to be significant in all conditions, even if to a different extent; but only hypoxia combined with the inhibition of the glycolytic pathway, has induced a significant expression of c-fos. It is very difficult to study hypoxic stimuli in 'in vitro' systems. Our study has compared three different models and the one combining gaseous hypoxia and hypoglycemic conditions seems to be very effective in stimulating early events involved in hypoxic phenomena such as phospholipase activation and the expression of the early gene c-fos.


Assuntos
Ácido Araquidônico/metabolismo , Hipoglicemia/complicações , Hipoglicemia/metabolismo , Hipóxia/complicações , Hipóxia/metabolismo , Proteínas Proto-Oncogênicas c-fos/metabolismo , Diferenciação Celular/efeitos dos fármacos , Ativação Enzimática/fisiologia , Glicólise/fisiologia , Humanos , Hipóxia/induzido quimicamente , Neuroblastoma/metabolismo , Neuroblastoma/patologia , Nitrogênio , Fosfolipases A/metabolismo , Fosfolipases A2 , Cianeto de Sódio , Fatores de Tempo , Tretinoína/farmacologia , Células Tumorais Cultivadas
5.
Brain Res Dev Brain Res ; 78(2): 169-74, 1994 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-8026072

RESUMO

The effects of different concentrations of exogenous platelet-activating factor (PAF) on the formation of arachidonic acid-cyclooxygenase metabolites and on the production of inositol phosphates have been investigated in a primary culture of rat astroglial cells. The cells were used at confluence and the purity was checked by immunostaining of the culture with specific antibodies against glial fibrillary acidic protein. Incubation of the cells with PAF (range 10(-9) to 10(-6) M) resulted in maximal accumulation of total inositol phosphate (620 +/- 60% increment over basal values, P < 0.001) at the concentration of 10(-8) M, after 1 min of stimulation. Smaller inositol phosphate accumulation occurred at higher concentrations of the agonist and at longer stimulation time. After 1 min of stimulation with PAF, the accumulation of the cyclooxygenase metabolites, thromboxane B2 (630 +/- 58 vs 20 +/- 2 pg/mg protein in non-stimulated samples) and 6-keto-prostaglandin F1 alpha (132 +/- 15 vs 55 +/- 7 pg/mg protein in non-stimulated samples) was also maximal at 10(-8) M concentration of the agonist. When the cultures were stimulated with PAF or Ca(2+)-ionophore after preincubation with equimolar concentration of the PAF inhibitor BN 52021, a significant inhibition in the synthesis of both inositol phosphates and cyclooxygenase metabolites occurred only in the PAF-stimulated cells.


Assuntos
Astrócitos/metabolismo , Diterpenos , Eicosanoides/metabolismo , Fosfatos de Inositol/metabolismo , Lactonas/farmacologia , Fator de Ativação de Plaquetas/farmacologia , 6-Cetoprostaglandina F1 alfa/metabolismo , Animais , Animais Recém-Nascidos , Astrócitos/efeitos dos fármacos , Calcimicina/farmacologia , Células Cultivadas , Relação Dose-Resposta a Droga , Ginkgolídeos , Inositol/metabolismo , Cinética , Fator de Ativação de Plaquetas/antagonistas & inibidores , Fator de Ativação de Plaquetas/metabolismo , Ratos , Tromboxano B2/metabolismo
6.
Neurosci Lett ; 289(2): 139-42, 2000 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-10904139

RESUMO

Testosterone metabolites (dihydrotestosterone, DHT) and 5 alpha-androstan-3 alpha,17 beta-diol (3 alpha-diol), but not testosterone itself, were shown to reduce the levels of very long chain fatty acids which accumulate in cultured skin fibroblasts from X-adrenoleukodystrophic patients (X-ALD). In addition, in X-ALD fibroblasts, testosterone is less actively converted into DHT vs. controls (skin fibroblasts retrieved from normal subjects) whereas the additional conversion of DHT to the final product 3 alpha-diol is enhanced. This is the first report of altered testosterone metabolism in X-ALD fibroblasts and of the effects of androgens in lowering the abnormal accumulation of very long chain fatty acids in this type of cells.


Assuntos
Adrenoleucodistrofia/metabolismo , Ácidos Graxos/metabolismo , Fibroblastos/metabolismo , Testosterona/metabolismo , Adrenoleucodistrofia/patologia , Criança , Di-Hidrotestosterona/metabolismo , Humanos , Pele/citologia , Pele/metabolismo , Pele/patologia
7.
Neurosci Lett ; 250(3): 145-8, 1998 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-9708853

RESUMO

The beta-oxidation of [3H] arachidonic acid (AA; 20:4 n-6) and the conversion of [1-14C]eicosapentaenoic acid (EPA, 20:5 n-3) to docosahexaenoic acid (DHA, 22:6 n-3) have been studied in skin fibroblasts from patients with inherited peroxisomal diseases, such as Zellweger (ZW) and X-linked adrenoleukodystrophy (X-ALD), from patients with Alzheimer's disease (AD), a non-inherited neuropathology, and from controls. EPA is not converted to DHA, while there is enhanced formation of the intermediate product 22:5 n-3 in ZW, when compared to X-ALD, AD and controls. We also confirmed that AA is not beta-oxidized to 4,7,10-hexadecatrienoic acid (16:3), a metabolite produced by peroxisomes, while being more effectively converted to the elongation product 22:4, in ZW, in comparison to X-ALD, AD and controls. The data demonstrate a defect in DHA synthesis and in AA beta-oxidation, and the occurrence of associated adaptative modifications in the metabolism of these long chain PUFA, in three Italian ZW patients.


Assuntos
Adrenoleucodistrofia/metabolismo , Doença de Alzheimer/metabolismo , Ácido Araquidônico/metabolismo , Ácidos Docosa-Hexaenoicos/metabolismo , Fibroblastos/metabolismo , Pele/metabolismo , Síndrome de Zellweger/metabolismo , Humanos , Oxirredução , Pele/citologia
8.
Thromb Res ; 87(3): 315-22, 1997 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-9263398

RESUMO

We have evaluated the effects of hydroxytyrosol (HT), a potent antioxidant present in olive oil, on the formation of arachidonic acid 5-lipoxygenase metabolites by leukocytes in vitro. HT, a simple phenolic compound, extracted from first-pressure oil, was isolated by HPLC and characterized by gas chromatography/mass spectrometry. HT inhibited in a dose-related manner the production of leukotriene B4 (LTB4) by calcium ionophore-stimulated leukocytes. As expected, similar inhibition was observed for omega-oxidized metabolites of LTB4, namely 20-hydroxy and 20-carboxy-LTB4. The results disclose a new biological activity of olive oil-derived phenols on leukocyte eicosanoid production.


Assuntos
Antioxidantes/farmacologia , Leucócitos/efeitos dos fármacos , Leucotrieno B4/biossíntese , Álcool Feniletílico/análogos & derivados , Óleos de Plantas/química , Araquidonato 5-Lipoxigenase/metabolismo , Cálcio/fisiologia , Cromatografia Líquida de Alta Pressão , Depressão Química , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Ionóforos/farmacologia , Leucócitos/metabolismo , Azeite de Oliva , Álcool Feniletílico/isolamento & purificação , Álcool Feniletílico/farmacologia
9.
Thromb Res ; 78(2): 151-60, 1995 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-7482432

RESUMO

This study was designed to investigate the in vitro effects of phenolic compounds extracted from olive oil and from olive derived fractions. More specifically, we investigated the effects on platelets of 2-(3,4-di-hydroxyphenyl)-ethanol (DHPE), a phenol component of extra-virgin olive oil with potent antioxidant properties. The following variables were studied: aggregation of platelet rich plasma (PRP) induced by ADP or collagen, and thromboxane B2 production by collagen or thrombin-stimulated PRP. In addition, thromboxane B2 and 12-hydroxyeicosatetraenoic acid (12-HETE) produced during blood clotting were measured in serum. Preincubation of PRP with DHPE for at least 10 min resulted in maximal inhibition of the various measured variables. The IC50s (concentration resulting in 50% inhibition) of DHPE for ADP or collagen-induced PRP aggregations were 23 and 67 microM, respectively. At 400 microM DHPE, a concentration which completely inhibited collagen-induced PRP aggregation, TxB2 production by collagen- or thrombin-stimulated PRP was inhibited by over 80 percent. At the same DHPE concentration, the accumulation of TxB2 and 12-HETE in serum was reduced by over 90 and 50 percent, respectively. We also tested the effects of PRP aggregation of oleuropein, another typical olive oil phenol, and of selected flavnoids (luteolin, apigenin, quercetin) and found them to be much less active. On the other hand a partially characterized phenol-enriched extract obtained from aqueous waste from olive oil showed rather potent activities. Our results are the first evidence that components of the phenolic fraction of olive oil can inhibit platelet function and eicosanoid formation in vitro, and that other, partially characterized, olive derivatives share these biological activities.


Assuntos
Antioxidantes/farmacologia , Eicosanoides/biossíntese , Álcool Feniletílico/análogos & derivados , Óleos de Plantas/química , Inibidores da Agregação Plaquetária/farmacologia , Agregação Plaquetária/efeitos dos fármacos , Ácido 12-Hidroxi-5,8,10,14-Eicosatetraenoico , Difosfato de Adenosina/farmacologia , Antioxidantes/isolamento & purificação , Colágeno/farmacologia , Flavonoides/isolamento & purificação , Flavonoides/farmacologia , Humanos , Ácidos Hidroxieicosatetraenoicos/biossíntese , Ácidos Hidroxieicosatetraenoicos/sangue , Glucosídeos Iridoides , Iridoides , Azeite de Oliva , Álcool Feniletílico/isolamento & purificação , Álcool Feniletílico/farmacologia , Extratos Vegetais/química , Inibidores da Agregação Plaquetária/isolamento & purificação , Piranos/isolamento & purificação , Piranos/farmacologia , Tromboxano B2/biossíntese , Tromboxano B2/sangue
10.
Cell Death Differ ; 16(1): 164-74, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18820643

RESUMO

In chronic myeloid leukemia K562 cells, differentiation is also blocked because of low levels of ganglioside GM3, derived by the high expression of sialidase Neu3 active on GM3. In this article, we studied the effects of Neu3 silencing (40-70% and 63-93% decrease in protein content and activity, respectively) in these cells. The effects were as follows: (a) gangliosides GM3, GM1, and sialosylnorhexaosylceramide increased markedly; (b) cell growth and [(3)H]thymidine incorporation diminished relevantly; (c) as mRNA, cyclin D2, and Myc were much less expressed, whereas cyclin D1 was expressed more like its inhibitor p21; (d) as mRNA, pro-apoptotic proteins Bax and Bad increased with concurrent decrease and increase in the anti-apoptotic proteins Bcl-2 and Bcl-XL, respectively; (e) the apoptosis inducers etoposide and staurosporine were active on Neu3 silencing cells but not on mock cells; (f) as mRNA, the megakaryocytic markers CD10, CD44, CD41, and CD61 increased similar to the case of mock cells stimulated with PMA; (g) the signaling cascades mediated by PLC-beta2, PKC, RAF, ERK1/2, RSK90, and JNK were largely activated. The induction of a GM3-rich ganglioside pattern in K562 cells by treatment with brefeldin A elicited a phenotype similar to that of Neu3 silencing cells. In conclusion, upon Neu3 silencing, K562 cells show a decrease in proliferation, propensity to undergo apoptosis, and megakaryocytic differentiation.


Assuntos
Apoptose/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Gangliosídeo G(M3)/farmacologia , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Regulação Leucêmica da Expressão Gênica/efeitos dos fármacos , Leucemia Mielogênica Crônica BCR-ABL Positiva/enzimologia , Megacariócitos/enzimologia , Proteínas de Neoplasias/biossíntese , Neuraminidase/biossíntese , Antígenos de Diferenciação/biossíntese , Antígenos de Diferenciação/genética , Apoptose/genética , Proliferação de Células/efeitos dos fármacos , Gangliosídeo G(M3)/metabolismo , Regulação Enzimológica da Expressão Gênica/genética , Regulação Leucêmica da Expressão Gênica/genética , Humanos , Células K562 , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Proteínas de Neoplasias/genética , Neuraminidase/antagonistas & inibidores , Neuraminidase/genética , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética
11.
Pharmacol Res ; 45(2): 125-8, 2002 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11846624

RESUMO

Adenosine plays an important role in cerebral ischemia by acting on its own receptors, in particular the A(2A)receptor. Its activation leads to excitatory amino acid release thus contributing to the ischemic damage. Blockade by specific antagonists may protect against cytotoxic injury. Our study was aimed to investigate the effect of the blockade of A(2A)receptors, by Sch 58261, on the expression of the early gene c-fos, in a model of permanent middle cerebral artery occlusion (pMCAo), in rats. In the pMCAo model, ischemia was induced in the right hemisphere whereas the contralateral one was considered the control. In our study, we have compared pMCAo rats, pMCAo rats treated with Sch 58261 and sham operated ones.C-fos was markedly expressed in the ischemic hemispheres, whereas lower levels were detected in the contralateral ones of the ischemic animals. The lowest bands were observed in sham operated rats. After treatment with Sch 58261, a considerable reduction in c-fos expression was observed in the ischemic hemispheres, whereas a limited effect was detected in the others. Our results suggest that inhibition of immediate-early gene expression by the A(2A)receptors antagonist Sch 58261 may contribute to its neuroprotective activity.


Assuntos
Isquemia Encefálica/metabolismo , Proteínas Proto-Oncogênicas c-fos/biossíntese , Antagonistas de Receptores Purinérgicos P1 , Pirimidinas/farmacologia , Triazóis/farmacologia , Animais , Western Blotting , Modelos Animais de Doenças , Eletroforese em Gel de Poliacrilamida , Masculino , Ratos , Ratos Sprague-Dawley , Receptor A2A de Adenosina
12.
Neurochem Res ; 19(9): 1187-93, 1994 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-7824073

RESUMO

Docosahexaenoic acid (22:6 n-3) was present in low concentrations in a primary culture of rat brain astroglial cells, when compared to brain cortex. We have thus supplemented these cells with this fatty acid and investigated the effects of its incorporation in cell phospholipids on the conversion of arachidonic acid, 20:4 n-6, through the cyclo and lipoxygenase pathways, after cell stimulation. Docosahexaenoic acid-enriched cells produced less thromboxane B2 and 6-keto-Prostaglandin F1 alpha and markedly less 12-hydroxyeicosatetraenoic acid than unsupplemented cells, after stimulation with the Ca(2+)-ionophore A23187. The production of 15-hydroxyeicosatetraenoic acid from arachidonic acid was slightly increased in docosahexaenoic acid-supplemented cells. We have also supplemented these cells with eicosapentaenoic acid (20:5 n-3) and, in addition to accumulation of this fatty acid in cell phospholipids, we found elevation of 22:5 n-3 and some increment of 22:6, confirming that glial cells are able to convert eicosapentaenoic acid to the long chain, more unsaturated derivatives. In conclusion, n-3 fatty acids, when supplemented to glial cells, appear to modulate the arachidonic acid cascade and to be converted through the elongation and desaturation pathways.


Assuntos
6-Cetoprostaglandina F1 alfa/biossíntese , Ácido Araquidônico/metabolismo , Astrócitos/efeitos dos fármacos , Calcimicina/farmacologia , Ácidos Docosa-Hexaenoicos/farmacologia , Tromboxano B2/biossíntese , Animais , Astrócitos/metabolismo , Células Cultivadas , Meios de Cultura , Ratos
13.
J Lipid Mediat Cell Signal ; 14(1-3): 39-44, 1996 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8906543

RESUMO

SK-N-BE cells were differentiated (D) to neurons with retinoic acid. Total n-6 polyunsaturated fatty acids (PUFA), especially arachidonic acid (AA), were increased in D versus ND cells. AA synthesis from linoleic acid (LA) and phospholipid (PL) synthesis from glycerol were initially elevated, whereas both processes were reduced approaching differentiation. At this stage, the incorporation of glycerol in triglycerides was enhanced. Formation of long chain PUFA and synthesis of acceptors (PL) for esterification, during RA-induced SK-N-BE differentiation, appear to be associated.


Assuntos
Ácido Araquidônico/metabolismo , Ceratolíticos/farmacologia , Metabolismo dos Lipídeos , Neuroblastoma/metabolismo , Tretinoína/farmacologia , Diferenciação Celular/efeitos dos fármacos , Humanos , Neuroblastoma/patologia , Células Tumorais Cultivadas
14.
J Neurochem ; 67(2): 549-56, 1996 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-8764579

RESUMO

We observed that retinoic acid, which differentiates the human neuroblastoma SK-N-BE into mature neurons, induced an elevation in levels of polyunsaturated fatty acids, especially arachidonic acid (20:4 n-6). This effect was not induced by phorbol myristate acetate, another differentiating agent. We then explored the effects of retinoic acid on the formation of arachidonic acid and of docosahexaenoic acid from precursors and on the de novo lipid synthesis from acetate at various stages of differentiation, which was assessed by morphological (cell number and neurite outgrowth) and biochemical (protein content and thymidine incorporation) criteria. At 3 days of incubation with retinoic acid, in the n-6 series, total conversion of linoleic acid, especially to 20:3 n-6, was elevated, in association with preferential incorporation of acetate into phospholipids; in contrast, at 8 days, synthesis of 20-carbon polyunsaturated fatty acids declined, in association with enhanced incorporation in triglycerides. In the n-3 series, eicosapentaenoic acid was converted to docosahexaenoic acid in SK-N-BE, but the conversion was not affected by retinoic acid. During the early stage of neuronal differentiation, therefore, enhanced production of 20-carbon polyunsaturated fatty acids from their precursors occurred, and newly formed fatty acids were preferentially incorporated in phospholipids, possibly in association with membrane deposition. When differentiation was completed, arachidonic acid formation and incorporation of acetate in phospholipids and cholesterol declined with enhanced labeling of storage lipids.


Assuntos
Ácido Araquidônico/metabolismo , Metabolismo dos Lipídeos , Neuroblastoma/metabolismo , Neurônios/metabolismo , Animais , Diferenciação Celular/efeitos dos fármacos , Células Cultivadas , Córtex Cerebral/citologia , Ácidos Graxos Insaturados/metabolismo , Humanos , Proteínas do Tecido Nervoso/metabolismo , Neurônios/citologia , Ratos , Tretinoína/farmacologia , Células Tumorais Cultivadas
15.
Biochem J ; 349(Pt 1): 343-51, 2000 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-10861246

RESUMO

Several mammalian sialidases have been described so far, suggesting the existence of numerous polypeptides with different tissue distributions, subcellular localizations and substrate specificities. Among these enzymes, plasma-membrane-associated sialidase(s) have a pivotal role in modulating the ganglioside content of the lipid bilayer, suggesting their involvement in the complex mechanisms governing cell-surface biological functions. Here we describe the identification and expression of a human plasma-membrane-associated sialidase, NEU3, isolated starting from an expressed sequence tag (EST) clone. The cDNA for this sialidase encodes a 428-residue protein containing a putative transmembrane helix, a YRIP (single-letter amino acid codes) motif and three Asp boxes characteristic of sialidases. The polypeptide shows high sequence identity (78%) with the membrane-associated sialidase recently purified and cloned from Bos taurus. Northern blot analysis showed a wide pattern of expression of the gene, in both adult and fetal human tissues. Transient expression in COS7 cells permitted the detection of a sialidase activity with high activity towards ganglioside substrates at a pH optimum of 3.8. Immunofluorescence staining of the transfected COS7 cells demonstrated the protein's localization in the plasma membrane.


Assuntos
Membrana Celular/química , Neuraminidase/biossíntese , Neuraminidase/química , Processamento Alternativo , Sequência de Aminoácidos , Animais , Sequência de Bases , Northern Blotting , Western Blotting , Células COS , Membrana Celular/metabolismo , Cromossomos Humanos Par 11 , Clonagem Molecular , DNA Complementar/metabolismo , Etiquetas de Sequências Expressas , Gangliosídeos/biossíntese , Gangliosídeos/genética , Biblioteca Gênica , Humanos , Concentração de Íons de Hidrogênio , Cinética , Bicamadas Lipídicas/química , Microscopia de Fluorescência , Modelos Genéticos , Dados de Sequência Molecular , Neuraminidase/genética , Análise de Sequência de DNA , Espectrometria de Fluorescência , Distribuição Tecidual , Transfecção
16.
Genomics ; 83(3): 445-53, 2004 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-14962670

RESUMO

Several mammalian sialidases have been cloned so far and here we describe the identification and expression of a new member of the human sialidase gene family. The NEU4 gene, identified by searching sequence databases for entries showing homologies to the human cytosolic sialidase NEU2, maps in 2q37 and encodes a 484-residue protein. The polypeptide contains all the typical sialidase amino acid motifs and, apart from an amino acid stretch that appears unique among mammalian sialidases, shows a high degree of homology for NEU2 and the plasma membrane-associated (NEU3) sialidases. RNA dot-blot analysis showed a low but wide expression pattern, with the highest level in liver. Transient transfection in COS7 cells allowed the detection of a sialidase activity toward the artificial substrate 4MU-NeuAc in the acidic range of pH. Immunofluorescence staining and Western blot analysis demonstrated the association of NEU4 with the inner cell membranes.


Assuntos
Clonagem Molecular , Neuraminidase/genética , Sequência de Aminoácidos , Animais , Células COS , Imunofluorescência , Vetores Genéticos , Humanos , Camundongos , Dados de Sequência Molecular , Neuraminidase/metabolismo , Plasmídeos , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Transfecção
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