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1.
Hum Genomics ; 18(1): 29, 2024 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-38520002

RESUMO

Chromosomal structural rearrangements consist of anomalies in genomic architecture that may or may not be associated with genetic material gain and loss. Evaluating the precise breakpoint is crucial from a diagnostic point of view, highlighting possible gene disruption and addressing to appropriate genotype-phenotype association. Structural rearrangements can either occur randomly within the genome or present with a recurrence, mainly due to peculiar genomic features of the surrounding regions. We report about three non-related individuals, harboring chromosomal structural rearrangements interrupting SETBP1, leading to gene haploinsufficiency. Two out of them resulted negative to Chromosomal Microarray Analysis (CMA), being the rearrangement balanced at a microarray resolution. The third one, presenting with a complex three-chromosome rearrangement, had been previously diagnosed with SETBP1 haploinsufficiency due to a partial gene deletion at one of the chromosomal breakpoints. We thoroughly characterized the rearrangements by means of Optical Genome Mapping (OGM) and Whole Genome Sequencing (WGS), providing details about the involved sequences and the underlying mechanisms. We propose structural variants as a recurrent event in SETBP1 haploinsufficiency, which may be overlooked by laboratory routine genomic analyses (CMA and Whole Exome Sequencing) or only partially determined when associated with genomic losses at breakpoints. We finally introduce a possible role of SETBP1 in a Noonan-like phenotype.


Assuntos
Aberrações Cromossômicas , Haploinsuficiência , Humanos , Haploinsuficiência/genética , Rearranjo Gênico , Cromossomos , Sequenciamento Completo do Genoma/métodos , Proteínas de Transporte/genética , Proteínas Nucleares/genética
2.
J Intellect Disabil Res ; 64(12): 956-969, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33034087

RESUMO

BACKGROUND: Ultrarare Marshall-Smith and Malan syndromes, caused by changes of the gene nuclear factor I X (NFIX), are characterised by intellectual disability (ID) and behavioural problems, although questions remain. Here, development and behaviour are studied and compared in a cross-sectional study, and results are presented with genetic findings. METHODS: Behavioural phenotypes are compared of eight individuals with Marshall-Smith syndrome (three male individuals) and seven with Malan syndrome (four male individuals). Long-term follow-up assessment of cognition and adaptive behaviour was possible in three individuals with Marshall-Smith syndrome. RESULTS: Marshall-Smith syndrome individuals have more severe ID, less adaptive behaviour, more impaired speech and less reciprocal interaction compared with individuals with Malan syndrome. Sensory processing difficulties occur in both syndromes. Follow-up measurement of cognition and adaptive behaviour in Marshall-Smith syndrome shows different individual learning curves over time. CONCLUSIONS: Results show significant between and within syndrome variability. Different NFIX variants underlie distinct clinical phenotypes leading to separate entities. Cognitive, adaptive and sensory impairments are common in both syndromes and increase the risk of challenging behaviour. This study highlights the value of considering behaviour within developmental and environmental context. To improve quality of life, adaptations to environment and treatment are suggested to create a better person-environment fit.


Assuntos
Anormalidades Múltiplas/epidemiologia , Anormalidades Múltiplas/fisiopatologia , Doenças do Desenvolvimento Ósseo/epidemiologia , Doenças do Desenvolvimento Ósseo/fisiopatologia , Anormalidades Craniofaciais/epidemiologia , Anormalidades Craniofaciais/fisiopatologia , Deficiência Intelectual/epidemiologia , Deficiência Intelectual/fisiopatologia , Transtornos Mentais/epidemiologia , Displasia Septo-Óptica/epidemiologia , Displasia Septo-Óptica/fisiopatologia , Distúrbios da Fala/epidemiologia , Adaptação Psicológica , Adolescente , Adulto , Criança , Pré-Escolar , Comorbidade , Estudos Transversais , Feminino , Seguimentos , Humanos , Masculino , Transtornos Mentais/fisiopatologia , Países Baixos/epidemiologia , Fenótipo , Distúrbios da Fala/fisiopatologia , Síndrome , Adulto Jovem
3.
Int J Obes (Lond) ; 40(6): 964-72, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-26830012

RESUMO

BACKGROUND: We have previously shown that antagonism of the mineralocorticoid receptor (MR) results in a potent antiadipogenic activity, in vitro and in vivo. Excessive glucocorticoid exposure is associated with obesity and related disorders in humans and mice. METHODS: In this study, responses to a novel combined glucocorticoid receptor (GR)/MR antagonist were investigated in a model of diet-induced obesity. Female 10-week-old C57BL/6J mice were fed with normal chow or a high-fat diet (HFD) for 9 weeks. Mice fed a HFD were concomitantly treated for 9 weeks with the GR antagonist mifepristone (80 mg kg(-1) per day) or the novel combined GR/MR antagonist CORT118335 (80 mg kg(-1) per day). Male, juvenile 6-week-old C57BL/6J mice fed HFD were treated with CORT118335 for 4 weeks. RESULTS: Mice fed a HFD showed a significant increase in total body weight and white fat mass, with impaired glucose tolerance and increased fat infiltration in livers. Interestingly, only CORT118335 completely prevented the HFD-induced weight gain and white fat deposition, whereas mifepristone showed no effect on body weight and modestly increased subcutaneous fat mass. Importantly, food intake was not affected by either treatment, and CORT118335 dramatically increased PGC-1α protein expression in adipose tissue, without any effect on UCP1. Both CORT118335 and mifepristone produced metabolic benefit, improving glucose tolerance, increasing adiponectin plasma levels, decreasing leptin and reducing mean adipocyte size. When tested in vitro, CORT118335 markedly reduced 3T3-L1 differentiation and reversed MR-mediated pro-adipogenic effects of aldosterone; differently, GR-mediated effects of dexamethasone were not antagonized by CORT118335, suggesting that it mostly acts as an antagonist of MR in cultured preadipocytes. CONCLUSIONS: Combined GR/MR pharmacological antagonism markedly reduced HFD-driven weight gain and fat mass expansion in mice through the increase in adipose PGC-1α, suggesting that both receptors represent strategic therapeutic targets to fight obesity. The effects of CORT118335 in adipocytes seem predominantly mediated by MR antagonism.


Assuntos
Tecido Adiposo/efeitos dos fármacos , Dieta Hiperlipídica , Mifepristona/farmacologia , Antagonistas de Receptores de Mineralocorticoides/farmacologia , Receptores de Glucocorticoides/antagonistas & inibidores , Timina/análogos & derivados , Aumento de Peso/efeitos dos fármacos , Animais , Modelos Animais de Doenças , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Timina/farmacologia
4.
Cell Death Dis ; 6: e1890, 2015 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-26379195

RESUMO

Ceramide regulates several different cellular responses including mechanisms leading to apoptosis. Serum- and glucocorticoid-inducible protein kinase (SGK)-1 is a serine threonine kinase, which activates survival pathways in response to stress stimuli. Recently, we demonstrated an anti-apoptotic role of SGK-1 in human umbilical endothelial cells treated with high glucose. In the present study, since ceramide induces apoptosis by multiple mechanisms in diabetes and its complication such as nephropathy, we aimed to investigate whether SGK-1 may protect even against apoptosis induced by ceramide in kidney cells. Human embryonic kidney (HEK)-293 cells stable transfected with SGK-1 wild type (SGK-1wt) and its dominant negative gene (SGK-1dn) have been used in this study. Apoptotic stimuli were induced by C2-ceramide and TNF-α to increase endogenous synthesis of ceramide. Upon activation with these stimuli, SGK-1wt transfected cells have a statistically significant reduction of apoptosis compared with SGK-1dn cells (P<0.001). This protection was dependent on activation of caspase-3 and Poly-ADP-ribose-polymerase-1 (PARP-1) cleavage. SGK-1 and AKT-1 two highly homologous kinases differently reacted to ceramide treatment, since SGK-1 increases in response to apoptotic stimulus while AKT-1 decreases. This enhancement of SGK-1 was dependent on p38-mitogen-activated-protein kinases (p38MAPK), cyclic-adenosine-monophosphate/protein kinase A (cAMP/PKA) and phosphoinositide-3-kinase (PI3K) pathways. Especially, by using selective LY294002 inhibitor, we demonstrated that the most involved pathway in the SGK-1 mediated process of protection was PI3K. Treatment with inhibitor of SGK-1 (GSK650394) significantly enhanced TNF-α-dependent apoptosis in HEK-293 cells overexpressing SGK-1wt. Caspase-3, -8 and -9 selective inhibitors confirmed that SGK-1 reduced the activation of caspase-dependent apoptosis, probably by both intrinsic and extrinsic pathways. In conclusion, we demonstrated that in kidney cells, overexpression of SGK-1 is protective against ceramide-induced apoptosis and the role of SGK-1 can be potentially explored as a therapeutic target in conditions like diabetes, where ceramide levels are increased.


Assuntos
Proteínas Imediatamente Precoces/genética , Proteínas Imediatamente Precoces/metabolismo , Rim/metabolismo , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Apoptose , Ceramidas , Células HEK293 , Humanos , Rim/citologia , Transfecção
5.
Acta Diabetol ; 49(5): 405-8, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21953423

RESUMO

Until early 2000, permanent and transient neonatal diabetes mellitus (NDM), defined as diabetes with onset within 6 weeks from birth that requires insulin therapy for at least 2 weeks, were considered exceedingly rare conditions, with a global incidence of 1:500,000-1:400,000 live births. The new definition of NDM recently adopted, that includes patients with diabetes onset within 6 months of age, has prompted studies that have set the incidence of the permanent form alone between 1:210,000 and 1:260,000 live births. Aim of the present work was to ascertain the incidence of NDM (i.e. permanent + transient form) in Italy for years 2005-2010. Patients referred to the Italian reference laboratory for NDM between years 2005 and 2010 and screened for mutations in common NDM genes (KCNJ11, ABCC8, and INS) and for uniparental isodisomy of chromosome 6 (UDP6) were reviewed. A questionnaire aimed at identifying NDM cases investigated in other laboratories was sent to 54 Italian reference centers for pediatric diabetes. Twenty-seven patients with NDM born between 2005 and 2010 were referred to the reference laboratory. In this group, a mutation of either KCNJ11, ABCC8 or INS was found in 18 patients, and a case with UDP6 was identified. Questionnaires revealed 4 additional cases with transient neonatal diabetes due to UDP6. Incidence of NDM was calculated at 1:90,000 (CI: 1:63,000-1:132,000) live births. Thus, with the definition currently in use, about 6 new cases with NDM are expected to be born in Italy each year.


Assuntos
Diabetes Mellitus Tipo 1/epidemiologia , Doenças do Recém-Nascido/epidemiologia , Diabetes Mellitus Tipo 1/genética , Feminino , Humanos , Incidência , Lactente , Recém-Nascido , Doenças do Recém-Nascido/genética , Itália/epidemiologia , Nascido Vivo , Masculino , Mutação
6.
Clin Ter ; 161(2): 169-71, 2010.
Artigo em Italiano | MEDLINE | ID: mdl-20499034

RESUMO

The Budd-Chiari Syndrome (BCS) and the splanchnic vein thrombosis are characterized by hepatic venous outflow obstruction, generally due to venous thrombosis. These rare diseases are usually caused by multiple concurrent factors, including acquired and inherited thrombophilias. Since the diagnosis of myeloproliferative neoplasms (MPNs) is often difficult in patients with BCS and splanchnic vein thrombosis because of spleen enlargement, secondary pancytopenia and bleeding disorders, recent observations have included in the diagnostic work-up the analysis of the JAK2 mutation. The revision of several recent reports clarify the importance of the JAK2V617F detection in the diagnostic work-up of the BCS and splanchnic vein thrombosis, allowing the demonstration of masked MPNs among these cases that may benefit, in the near future, of target molecular therapies directed toward the JAK2 mutation.


Assuntos
Neoplasias da Medula Óssea/diagnóstico , Neoplasias da Medula Óssea/genética , Síndrome de Budd-Chiari/diagnóstico , Síndrome de Budd-Chiari/genética , Janus Quinase 2/genética , Transtornos Mieloproliferativos/diagnóstico , Transtornos Mieloproliferativos/genética , Circulação Esplâncnica , Trombose Venosa/diagnóstico , Trombose Venosa/genética , Diagnóstico Diferencial , Humanos
7.
Climacteric ; 11(3): 258-64, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18568791

RESUMO

Beside their role in the control of water and electrolyte homeostasis, recent data clearly indicate that aldosterone and the mineralocorticoid receptor (MR) are involved in adipocyte biology. It has been recently shown that aldosterone promotes white and brown adipocyte differentiation in vitro through specific activation of the MR. In addition, a non-epithelial pro-inflammatory role for MR activation has been recently inferred from studies on mineralocorticoid/salt administration in experimental animal models and from clinical studies. The mineralocorticoid system could hence represent a potential target for new therapeutic strategies in obesity and the metabolic syndrome. Progesterone has high affinity for the MR and is a natural antagonist of aldosterone. Differently from classic synthetic progestins, which are devoid of antimineralocorticoid properties, progesterone and new progestogens show remarkable antimineralocorticoid effects. Here, we discuss the potential role of the antimineralocorticoid properties of progestogens in the control of body weight, adipose tissue proliferation and salt sensitivity; their therapeutic use in postmenopausal women, as well as in women affected by polycystic ovary syndrome, may open new and unexpected possibilities in the treatment of related metabolic disorders.


Assuntos
Tecido Adiposo/efeitos dos fármacos , Progestinas/farmacologia , Receptores de Mineralocorticoides , Cloreto de Sódio na Dieta/efeitos adversos , Equilíbrio Hidroeletrolítico/efeitos dos fármacos , Tecido Adiposo/metabolismo , Animais , Diferenciação Celular/efeitos dos fármacos , Feminino , Humanos , Síndrome Metabólica/tratamento farmacológico , Antagonistas de Receptores de Mineralocorticoides/farmacologia , Obesidade/tratamento farmacológico , Progestinas/fisiologia , Receptores de Mineralocorticoides/efeitos dos fármacos , Receptores de Mineralocorticoides/metabolismo , Equilíbrio Hidroeletrolítico/fisiologia
8.
Ann Oncol ; 17(4): 676-82, 2006 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16446317

RESUMO

BACKGROUND: It is still unclear the actual contribute of dose intensity (DI), dose size (DS) and dose density (DD) in the conventional chemotherapy of large, B-cell non-Hodgkin lymphomas. METHODS: A prospective, randomized trial compared the cyclic schedule of ProMECE-CytaBOM chemotherapy (cyc-PC, 6 cycles) with a modified version of it, which administered the same drugs sequentially (seq-PC), with the same planned cumulative DI and an 83% DD, within the same time frame (113 days), but with three times higher DS of all the drugs except vincristine. RESULTS: Fifty-six patients received cyc-PC and 52 seq-PC. The actual mean cumulative DI was 0.79 +/- 0.15 with cyc-PC, 0.78 +/- 0.17 with seq-PC. Response was complete in 59% and 52%, partial in 20% and 21%, null in 5% and 6%, respectively. There were four toxic deaths (two per arm). Relapses occurred in 36% and 37%, respectively. Toxicity was similar in both arms. Overall, failure-free, progression-free and disease-free survival (median follow-up: 54 months) were statistically indifferent. CONCLUSIONS: The very similar DI actually delivered in both arm seems to be the main common determinant of the indifferent results recorded. Increasing DS--at least within the limits clinically attainable without stem cell rescue--does not improve results.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Linfoma de Células B/tratamento farmacológico , Linfoma Difuso de Grandes Células B/tratamento farmacológico , Adulto , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Bleomicina/administração & dosagem , Ciclofosfamida/administração & dosagem , Citarabina/administração & dosagem , Relação Dose-Resposta a Droga , Epirubicina/administração & dosagem , Etoposídeo/administração & dosagem , Feminino , Humanos , Masculino , Metotrexato/administração & dosagem , Pessoa de Meia-Idade , Prednisona/administração & dosagem , Vincristina/administração & dosagem
9.
Bone Marrow Transplant ; 37(3): 283-8, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16327815

RESUMO

GISL recently conducted an exhaustive survey of 1078 patients with Hodgkin's Lymphoma (HL) enrolled between 1988 and 2002 in different prospective trials. Treatment failure was observed in 82 out of 1078 patients; of these 82 patients with refractory HL, complete information was available for 72, who form the evaluable population of the present study. After the initial therapy failure, 51 patients were treated with conventional salvage chemotherapy (CC) (n = 24) or high-dose chemotherapy (HDC) (n = 27); 4-year overall survival (OS) was 81% in the HDC group versus 38% in the CC group (P = 0.019). The remaining 21 patients had rapidly progressive disease and died. After a median follow-up of 2.8 years, the projected OS for all 72 patients is 58 and 49% at 3 and 5 years, respectively. Age <45 years, the absence of systemic symptoms and a PS <1 predicted a significantly longer OS. Interestingly, the majority of patients with two or three negative prognostic factors did not receive potentially curative therapy. In conclusion, HDC seems to be a reasonable option for selected patients with refractory HL, although the majority of them did not receive a transplant. Finally, patients with a high-risk score had little chance of receiving potentially curative treatment.


Assuntos
Coleta de Dados , Doença de Hodgkin/mortalidade , Doença de Hodgkin/terapia , Transplante de Células-Tronco , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Terapia de Salvação/métodos , Terapia de Salvação/mortalidade , Transplante de Células-Tronco/métodos , Transplante de Células-Tronco/mortalidade , Taxa de Sobrevida , Transplante Autólogo
10.
Hum Genet ; 115(5): 357-71, 2004 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-15322918

RESUMO

In order to attain a finer reconstruction of the peopling of southern and central-eastern Europe from the Levant, we determined the frequencies of eight lineages internal to the Y chromosomal haplogroup J, defined by biallelic markers, in 22 population samples obtained with a fine-grained sampling scheme. Our results partially resolve a major multifurcation of lineages within the haplogroup. Analyses of molecular variance show that the area covered by haplogroup J dispersal is characterized by a significant degree of molecular radiation for unique event polymorphisms within the haplogroup, with a higher incidence of the most derived sub-haplogroups on the northern Mediterranean coast, from Turkey westward; here, J diversity is not simply a subset of that present in the area in which this haplogroup first originated. Dating estimates, based on simple tandem repeat loci (STR) diversity within each lineage, confirmed the presence of a major population structuring at the time of spread of haplogroup J in Europe and a punctuation in the peopling of this continent in the post-Neolithic, compatible with the expansion of the Greek world. We also present here, for the first time, a novel method for comparative dating of lineages, free of assumptions of STR mutation rates.


Assuntos
Cromossomos Humanos Y , Haplótipos , Filogenia , África do Norte , Emigração e Imigração , Europa (Continente) , Variação Genética , Humanos , Masculino , Polimorfismo Genético , Sequências de Repetição em Tandem
11.
Clin Exp Obstet Gynecol ; 31(2): 117-9, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15266764

RESUMO

A vast literature documents the role of melatonin in human reproductive function including: a) the relation between melatonin and the menstrual cycle in relation to the peak time of luteinizing hormone in the middle of the cycle; b) the varying concentrations of melatonin in the control of puberty; c) the fewer conceptions in some artic populations where melatonin is connected significantly to seasonal photoperiodicity during the months of the polar nights. The aim of this paper is to report our findings on the pharmacological action of this molecule on reproduction in which gonadal activity is clearly connected to photoperiodicity. We used polymer bioimplants programmed for the sustained release of melatonin for experimental gynecologic protocols. These implants had beneficial results with respect to the use of progestinics because melatonin allowed ovarian activity to be induced for at least two to three consecutive cycles with one single bioimplant. We thought it indispensable to use pharmacological systems with a sustained release because different preliminary tests showed that the half-life of melatonin is limited at maximum to two to three hours and, consequently, any other tested modalities of administration would not provide any appreciable results for our study. As a model for our research we used goats to administer melatonin via targeted programs since these animals clearly respond (even against the rule of the light/dark relation) in contrast to humans in whom response is less evident. For controls, after inserting bioimplants in the animals, we tested their efficiency in vitro and subsequently in vivo, evaluating blood parameters and pharmacological effects of melatonin occurring during the treatment. The final results proved to be interesting in relation to reproductive activity in that regular and programmed births were achieved.


Assuntos
Fármacos para a Fertilidade Feminina/farmacocinética , Cabras/fisiologia , Melatonina/farmacologia , Reprodução/efeitos dos fármacos , Implantes Absorvíveis , Animais , Preparações de Ação Retardada , Feminino , Fármacos para a Fertilidade Feminina/administração & dosagem , Melatonina/administração & dosagem , Melatonina/farmacocinética , Gravidez , Taxa de Gravidez
12.
Mol Phylogenet Evol ; 28(3): 387-95, 2003 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12927125

RESUMO

We explored the spatial distribution of human Y chromosomal diversity on a microgeographic scale, by typing 30 population samples from closely spaced locations in Italy and Greece for 9 haplogroups and their internal microsatellite variation. We confirm a significant difference in the composition of the Y chromosomal gene pools of the two countries. However, within each country, heterogeneity is not organized along the lines of clinal variation deduced from studies on larger spatial scales. Microsatellite data indicate that local increases of haplogroup frequencies can be often explained by a limited number of founders. We conclude that local founder or drift effects are the main determinants in shaping the microgeographic Y chromosomal diversity.


Assuntos
Cromossomos Humanos Y/genética , Efeito Fundador , Deriva Genética , Variação Genética , Análise de Variância , Primers do DNA , Geografia , Grécia , Haplótipos/genética , Humanos , Itália , Masculino , Repetições de Microssatélites/genética , Polimorfismo de Nucleotídeo Único , Dinâmica Populacional
13.
Clin Exp Obstet Gynecol ; 30(2-3): 130-6, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-12854860

RESUMO

In this study, the pharmacologic substance reduced glutathione (GSH) was used in men with hypofertility problems linked to varicocele, in bulls with spermatozoa hypomobility due to varicocele, and in rabbits with dispermy caused by cryptorchidism. An efficacious therapeutic effect of increased motility of the spermatozoa was seen in subjects who were submitted to appropriate doses of glutathione I.M. GSH also showed some neutralizing effect on the catabolytes produced during spontaneous or induced peroxidation processes of the unsaturated lipids contained in the membranes of male germinal cells. The genetic aspects of the involved enzymes were also evaluated and the research was extended in vitro by incubating samples of spermatozoa with arachidonic acid homogenates, L-tryptophan, hematein, and with an addition of glutathione. The results showed that polynsaturated fatty acid metabolic substances (PUFA) play an important role in the acrosomal reaction of spermatozoa and that GSH has a determining role in increasing the motility of spermatozoa with consequent improved fertilization. The spermatozoa of bulls provided us with a valid model to study for the morphostructural, biochemical and pharmacological analyses of human spermatozoa.


Assuntos
Glutationa/farmacologia , Infertilidade Masculina/genética , Infertilidade Masculina/terapia , Motilidade dos Espermatozoides/efeitos dos fármacos , Espermatozoides/enzimologia , Animais , Antioxidantes/farmacologia , Bovinos , Criopreservação , Criptorquidismo/complicações , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Fertilização , Glucosefosfato Desidrogenase/metabolismo , Glutationa/uso terapêutico , Humanos , Infertilidade Masculina/etiologia , L-Lactato Desidrogenase/metabolismo , Peroxidação de Lipídeos , Masculino , Oxirredução , Coelhos , Espermatozoides/efeitos dos fármacos , Espermatozoides/fisiologia , Varicocele/complicações
14.
J Immunother ; 20(6): 431-6, 1997 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9409448

RESUMO

Small peptides, 8-10 amino acids long, derived from degradation of cytoplasmic proteins by a proteasome-proteinase complex, are usually presented and recognized by CD8+ cytolytic T lymphocytes (CTLs) associated with major histocompatibility complex (MHC) class I molecules. Recently synthetic peptides were used for the in vitro induction of tumor-specific CTLs, offering another strategy in the study of the immune-response repertoire and providing a new tool in cancer vaccination and immunotherapy. Peptides derived from otherwise normal proteins, overexpressed in many tumors as products of the protooncogene, may represent a target for an immune response. This is the case of HER-2/neu gene (also known as ErbB-2), encoding a cysteine-rich glycoprotein transmembrane receptor with tyrosine kinase activity (gp185neu). Recent data, demonstrating that HLA-A2.1-related peptides are able to stimulate in vitro CD8+ lymphocytes, Prompted us to study the binding to HLA-A2.1 molecules of several gp185 synthetic peptides containing a cystein residue and to define the relevance of this amino acid residue in the reduced or oxidated form of the sulfhydryl group. We found that monomers and their homodimers, linked by a disulfide bridge, bind to HLA-A2.1 molecules with overlapping affinity. These results suggest that additional amino acids of the nonapeptide do not prevent the binding and the HLA refolding through chemical or sterical interactions. This might be of particular relevance for the in vivo processing of cysteine-rich proteins. Because ErbB-2 molecules, as tumor-differentiation antigens in melanoma, are cysteine-rich molecules, it may be relevant to evaluate the possible role of the cystine residues interacting with the T-cell receptor. The recognition of these heterodimers by CD8+ lymphocytes will require functional in vivo studies.


Assuntos
Cisteína/metabolismo , Antígeno HLA-A2/metabolismo , Antígenos de Histocompatibilidade Classe I/metabolismo , Oligopeptídeos/metabolismo , Sequência de Aminoácidos , Dimerização , Glutationa/metabolismo , Humanos , Fragmentos de Peptídeos/metabolismo , Receptor ErbB-2/química
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