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1.
J Biomed Mater Res A ; 2024 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-38775427

RESUMO

In this work, a sequential covalent immobilization of graphene oxide (GO) and hyaluronic acid (HA) is performed to obtain a biocompatible wear-resistant nanocoating on the surface of the biomedical grade cobalt-chrome (CoCr) alloy. Nanocoated CoCr surfaces were characterized by Raman spectroscopy and electrochemical impedance spectroscopy (EIS) in 3 g/L HA electrolyte. Tribocorrosion tests of the nanocoated CoCr surfaces were carried out in a pin on flat tribometer. The biological response of covalently HA/GO biofunctionalized CoCr surfaces with and without wear-corrosion processes was studied through the analysis of the proteome of macrophages. Raman spectra revealed characteristic bands of GO and HA on the functionalized CoCr surfaces. The electrochemical response by EIS showed a stable and protective behavior over 23 days in the simulated biological environment. HA/GO covalently immobilized on CoCr alloy is able to protect the surface and reduce the wear volume released under tribocorrosion tests. Unsupervised classification analysis of the macrophage proteome via hierarchical clustering and principal component analysis (PCA) revealed that the covalent functionalization on CoCr enhances the macrophage biocompatibility in vitro. On the other hand, disruption of the HA/GO nanocoating by tribocorrosion processes induced a macrophage proteome which was differently clustered and was distantly located in the PCA space. In addition, tribocorrosion induced an increase in the percentage of upregulated and downregulated proteins in the macrophage proteome, revealing that disruption of the covalent nanocoating impacts the macrophage proteome. Although macrophage inflammation induced by tribocorrosion of HA/GO/CoCr surfaces is observed, it is ameliorated by the covalently grafting of HA, which provides immunomodulation by eliciting downregulations in characteristic pro-inflammatory signaling involved in inflammation and aseptic loosening of CoCr joint arthroplasties. Covalent HA/GO nanocoating on CoCr provides potential applications for in vivo joint prostheses led a reduced metal-induced inflammation and degradation by wear-corrosion.

2.
Funct Neurol ; 33(2): 67-72, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29984683

RESUMO

Hyperglycemia-associated chorea-ballism (HCB) is an infrequent neurological syndrome whose pathophysiology remains poorly understood. Positron emission tomography (PET) studies have offered valuable information regarding regional glucose metabolism. The studies included were published between 1980-2017 and reported demographic, clinical, laboratory and imaging data from patients with HCB in whom a PET scan had been performed. Eleven patients were evaluated (women 82%, Asian origin 91%, mean age 71 years). The main findings were an increase in glucose metabolism at the contralateral motor cortex related to recent episodes of hemiballism-hemichorea in 2 patients, and an altered metabolism in the affected basal ganglia in all of them: decreased in 10 patients (91%) and increased in 1 (9%). However during the acute period the patients showed only an increased metabolism, or even no changes. Contrary to what has previously been suggested in a metabolic failure hypothesis, changes in glucose metabolism in the basal ganglia may not be a key factor in the pathogenesis of HCB, and may potentially be a direct result of histological changes such as cellular ischemia and gliosis related to HCB development.


Assuntos
Gânglios da Base/metabolismo , Coreia/metabolismo , Hiperglicemia/metabolismo , Córtex Motor/metabolismo , Tomografia por Emissão de Pósitrons , Gânglios da Base/diagnóstico por imagem , Coreia/diagnóstico por imagem , Humanos , Hiperglicemia/diagnóstico por imagem , Córtex Motor/diagnóstico por imagem
3.
Rev. int. med. cienc. act. fis. deporte ; 17(65): 27-41, mar. 2017. tab, graf
Artigo em Espanhol | IBECS | ID: ibc-161553

RESUMO

El objetivo de este trabajo es crear ecuaciones que estimen las medidas de los pliegues cutáneos para escolares de 6 a 13 años de edad. Como resultado se obtuvieron catorce ecuaciones que estiman algunos pliegues cutáneos. Las ecuaciones se validaron con muestras aleatorias de 479 niñas y 541 niños del estado de Puebla y otras 2 muestras aleatorias del estado de Veracruz con 155 niñas y 146 niños respectivamente; las mediciones directas se realizaron con la metodología y unidades ISAK (International Society for the Advancement of Kinanthropometry) (AU)


The aim of this paper is to create equations that predict the skinfold measures for school children 6 to 13 years old. Fourteen resulting equations were derived to estimate some measures of skinfold. The equations were validated with random samples of 479 girls and 541 boys in the state of Puebla and 2 other random samples of the state of Veracruz with 155 girls and 146 boys respectively; direct measurements were performed with the methodology and units ISAK (International Society for the Advancement of Kinanthropometry (AU)


Assuntos
Humanos , Masculino , Feminino , Criança , Adolescente , Dobras Cutâneas , Educação Física e Treinamento/métodos , Modelos Teóricos/métodos , Antropometria/instrumentação , Desenvolvimento Infantil/fisiologia , Pesos e Medidas Corporais , Análise de Regressão , Peso-Estatura/fisiologia , 28599 , Estatísticas não Paramétricas
4.
Scand J Med Sci Sports ; 26(11): 1313-1320, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26634957

RESUMO

To determine the influence of androgen receptor CAG and GGN repeat polymorphisms on fat mass and maximal fat oxidation (MFO), CAG and GGN repeat lengths were measured in 128 young boys, from which longitudinal data were obtained in 45 of them [mean ± SD: 12.8 ± 3.6 years old at recruitment, and 27.0 ± 4.8 years old at adult age]. Subjects were grouped as CAG short (CAGS ) if harboring repeat lengths ≤ 21, the rest as CAG long (CAGL ); and GGN short (GGNS ) if GGN repeat lengths ≤ 23, or long if > 23 (GGNL ). CAGS and GGNS were associated with lower adiposity than CAGL or GGNL (P < 0.05). There was an association between the logarithm of CAG repeats polymorphism and the changes of body mass (r = 0.34, P = 0.03). At adult age, CAGS men showed lower accumulation of total body and trunk fat mass, and lower resting metabolic rate (RMR) and MFO per kg of total lean mass compared with CAGL (P < 0.05). GGNS men also showed lower percentage of body fat (P < 0.05). In summary, androgen receptor CAG and GGN repeat polymorphisms are associated with RMR, MFO, fat mass, and its regional distribution in healthy male adolescents, influencing fat accumulation from adolescence to adult age.


Assuntos
Adiposidade/genética , Metabolismo Basal/genética , Receptores Androgênicos/genética , Absorciometria de Fóton , Adolescente , Adulto , Composição Corporal/genética , Distribuição da Gordura Corporal , Calorimetria Indireta , Criança , Humanos , Estudos Longitudinais , Masculino , Oxirredução , Aptidão Física , Polimorfismo Genético , Adulto Jovem
5.
Rom J Intern Med ; 53(2): 128-32, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26402981

RESUMO

Vasculitis in rheumatoid arthritis (rheumatoid vasculitis, RV) has a heterogeneous clinical presentation that includes skin disorders, neuropathy, eye symptoms and systemic inflammation. Rheumatoid vasculitis is an unusual complication of longstanding, severe rheumatoid arthritis (RA). While RA affects the body's joints, vasculitis is a condition in which blood vessels become inflamed. Rheumatoid vasculitis occurs in approximately 2 to 5% of patients who have RA. The blood vessels most often involved are arteries that bring blood to the skin, nerves, and internal organs. Veins can also be involved. Rheumatoid vasculitis is skin condition that is a typical feature of RA, presenting as peripheral vascular lesions that are localized (purpura, cutaneous ulceration, and gangrene of the distal parts of the extremities). The cause of RV is unknown, but given the prominence of immune components and the pathologic changes in involved blood vessels, an autoimmune process is suggested. Compared to other forms of vasculitis, there has been relativejy little research in recent years on the specific entity of RV. There is some evidence that the incidence of RV has decreased over the past several decades, perhaps because of a better treatment of the underlying RA. In the present review, we discuss the clinical features, laboratory tests, the pathogenesis of RV.


Assuntos
Vasculite Reumatoide/diagnóstico , Humanos , Vasculite Reumatoide/epidemiologia , Vasculite Reumatoide/etiologia
6.
Int J Biol Markers ; 27(3): e219-26, 2012 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-23015403

RESUMO

BACKGROUND: The sequences of many human genes that encode proteins involved in cancer contain polymorphic microsatellites. Variations in microsatellite length may constitute risk factors in several human diseases, a possibility that has been little explored in breast cancer. Among the genes that contain polymorphic microsatellites are EGFR, NOTCH4 and E2F4. The length of some of these microsatellites has been associated with breast cancer risk. PURPOSE AND METHODS: To determine whether the length of the microsatellites (CA)n in EGFR, (CTG)n in NOTCH4 and (AGC)n in E2F4 was associated with breast cancer risk, we genotyped these 3 microsatellites in 212 women with breast cancer and a control group of 308 women from the general population who did not have this disease. RESULTS AND CONCLUSIONS: The allelic distribution observed for the 3 microsatellites matched that found in other white populations, with the exception of some (AGC)n alleles in E2F4, which have not been described previously. The length of (CA)n in EGFR and (CTG)n in NOTCH4 was not associated with breast cancer (OR=0.99; 95% CI 0.59-1.37; p=0.619 and OR=1.08; 95% CI 0.71-1.65; p=0.725, respectively). Short alleles (<13 repeats) of (AGC)n in E2F4 were less frequent in women with cancer than in the control sample.


Assuntos
Neoplasias da Mama/genética , Fator de Transcrição E2F4/genética , Repetições de Microssatélites , Proteínas Proto-Oncogênicas/genética , Receptores Notch/genética , Receptores de Fatores de Crescimento do Endotélio Vascular/genética , Adulto , Neoplasias da Mama/metabolismo , Fator de Transcrição E2F4/metabolismo , Feminino , Humanos , Pessoa de Meia-Idade , Polimorfismo Genético , Proteínas Proto-Oncogênicas/metabolismo , Receptor Notch4 , Receptores Notch/metabolismo , Receptores de Fatores de Crescimento do Endotélio Vascular/metabolismo , Fatores de Risco
7.
Nutr Metab Cardiovasc Dis ; 21(1): 18-24, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19822408

RESUMO

BACKGROUND AND AIMS: Cholesteryl ester transfer protein (CETP) is an enzyme with a key role in lipoprotein metabolism. A common genetic polymorphism, the Taq 1B, influences CETP activity and HDL-cholesterol levels, with individual homozygotes for the B1 allele exhibiting higher enzyme activity and lower HDL-cholesterol levels than carriers of at least one B2 allele. Our aim was to analyze the influence of Taq 1B CETP polymorphism on cardiovascular risk factors in a representative sample of adult subjects from Canary population. METHODS AND RESULT: A total of 518 adult subjects from the Canary Islands, enrolled in a nutritional survey (the ENCA study), were included. The Taq 1B polymorphism was analyzed by PCR-RFLP. Compared with individuals with at least one B2 allele, and after adjusting for age, sex, BMI, waist perimeter, smoking and alcohol intake, carriers of the B1B1 genotype showed lower HDL-cholesterol levels (geometric mean (95% CI): 46.6 (44.5-48.8) vs. 50.6 (49.1-52.9)mg/dl; P=0.003); and higher insulin (geometric mean (95% CI): 11.1 (10.5-11.9) vs. 10.0 (9.5-10.5µU/ml; P=0.008) and HOMA levels (geometric mean (95% CI): 2.3 (2.1-2.5) vs. 2.1 (1.9-2.1); P=0.009). In addition, the B1B1 genotype was more frequent in individuals who had low levels of HDL-cholesterol according to the National Cholesterol Education Program Adult Treatment Panel III (NCEP-ATP III) criteria (Odds Ratio (OR): 1.563; 95% CI: 1.04-2.34; P=0.030), and in those included in the upper quartile of insulinemia (OR: 1.90; 95% CI: 1.20-3.03; P=0.007) and HOMA (OR: 1.61; 95% CI: 1.02-2.57; P=0.043). CONCLUSION: The observed influence of Taq 1B polymorphism on insulin levels and HOMA highlights the possible role of CETP in the regulation of glucose homeostasis.


Assuntos
Proteínas de Transferência de Ésteres de Colesterol/genética , Homeostase/genética , Homeostase/fisiologia , Insulina/sangue , Insulina/genética , Adolescente , Adulto , Idoso , Antropometria , Glicemia/metabolismo , HDL-Colesterol/sangue , HDL-Colesterol/genética , Estudos de Coortes , DNA/genética , Feminino , Humanos , Resistência à Insulina/genética , Resistência à Insulina/fisiologia , Metabolismo dos Lipídeos/genética , Metabolismo dos Lipídeos/fisiologia , Masculino , Pessoa de Meia-Idade , Inquéritos Nutricionais , Polimorfismo Genético/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Espanha/epidemiologia , Adulto Jovem
8.
Br J Sports Med ; 45(2): 95-100, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19617210

RESUMO

The exon-1 of the androgen receptor (AR) gene contains two repeat length polymorphisms which modify either the amount of AR protein inside the cell (GGN(n), polyglycine) or its transcriptional activity (CAG(n), polyglutamine). Shorter CAG and/or GGN repeats provide stronger androgen signalling and vice versa. To test the hypothesis that CAG and GGN repeat AR polymorphisms affect muscle mass and various variables of muscular strength phenotype traits, the length of CAG and GGN repeats was determined by PCR and fragment analysis and confirmed by DNA sequencing of selected samples in 282 men (28.6 ± 7.6 years). Individuals were grouped as CAG short (CAG(S)) if harbouring repeat lengths of ≤ 21 and CAG long (CAG(L)) if CAG >21. GGN was considered short (GGN(S)) or long (GGN(L)) if GGN ≤ 23 or >23, respectively. No significant differences in lean body mass or fitness were observed between the CAG(S) and CAG(L) groups, or between GGN(S) and GGN(L) groups, but a trend for a correlation was found for the GGN repeat and lean mass of the extremities (r=-0.11, p=0.06). In summary, the lengths of CAG and GGN repeat of the AR gene do not appear to influence lean mass or fitness in young men.


Assuntos
Força Muscular/genética , Músculo Esquelético/anatomia & histologia , Aptidão Física/fisiologia , Polimorfismo Genético/genética , Receptores Androgênicos/genética , Adulto , Desempenho Atlético/fisiologia , Composição Corporal/genética , Metabolismo Energético/genética , Humanos , Masculino , Músculo Esquelético/fisiologia , Magreza/genética , Repetições de Trinucleotídeos/genética , Adulto Jovem
9.
Immunol Lett ; 133(1): 6-13, 2010 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-20637236

RESUMO

Autoimmune diseases occur more in women than in men, and this may be attributable to the role of estrogens. Androgens promote autoimmune diseases with a profile of type 1 cytokines, such as rheumatoid arthritis, whereas estrogens promote autoimmune diseases with a type 2 cytokine profile, like systemic lupus erythematosus. Both androgens and estrogens regulate the Th1/Th2 balance. Type 1 autoimmune diseases are improved when decrease type 1 cytokines (i.e. during fasting), or when there is a rise in type 2 cytokines (increased estrogens, as in pregnancy). Type 2 autoimmune diseases improve when type 2 cytokines are diminished (decreased estrogen, as in post-partum period) or when type 1 response is stimulated.


Assuntos
Androgênios/metabolismo , Artrite Reumatoide/imunologia , Estrogênios/metabolismo , Lúpus Eritematoso Sistêmico/imunologia , Equilíbrio Th1-Th2 , Androgênios/imunologia , Animais , Artrite Reumatoide/epidemiologia , Autoimunidade , Estrogênios/imunologia , Feminino , Humanos , Lúpus Eritematoso Sistêmico/epidemiologia , Masculino , Gravidez/imunologia , Fatores Sexuais
10.
Oncol Rep ; 22(6): 1425-33, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19885596

RESUMO

Breast cancer (BC) is a complex disease influenced by environmental and genetic factors. The disease has important genetic and environmental components, most of them are still unknown. An important role of gene polymorphisms related to the risk of developing BC has been reported. However, the results have been controversial. We investigated the association of TSER, MTHFR C677T, p53 codon 72 and MDR1 C3435T gene polymorphisms with breast carcinoma in women from Canary Islands (Spain). Blood samples collected from 135 patients with BC and 304 healthy controls all of them Caucasian, were analyzed through polymerase chain reaction-restriction fragment length polymorphism. Subsequently, a structured questionnaire including patient history and risk factors in relation to BC development was filled out. Allelic frequencies of these genetic variations were: TSER, (2) 0.55 and (3) 0.45 in cases, 0.49 and 0.51 respectively in controls (P=0.240); MTHFR C677T, (C) 0.63 and (T) 0.37 in cases, 0.60 and 0.40 respectively in controls (P=0.568); p53 Arg72Pro, (Arg) 0.74 and (Pro) 0.26 in cases and controls (P=0.910); MDR1 C3435T, (C) 0.52 and (T) 0.48 in cases, 0.55 and 0.45 respectively in controls (P=0.523). We did not observe any gene polymorphism as a risk factor to develop BC. A statistical association was observed between p53 codon 72 polymorphism and family history of breast cancer in both groups, as well as between MDR1 C3435T and smoking habits in cases (P<0.05). Gene polymorphisms vary by regions. The present study contributes to the characterization of the genetic pattern of the Canary population.


Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/genética , Neoplasias da Mama/genética , Metilenotetra-Hidrofolato Redutase (NADPH2)/genética , Polimorfismo Genético , Timidilato Sintase/genética , Proteína Supressora de Tumor p53/genética , Subfamília B de Transportador de Cassetes de Ligação de ATP , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/biossíntese , Adulto , Idoso , Estudos de Casos e Controles , Códon , Feminino , Frequência do Gene , Humanos , Metilenotetra-Hidrofolato Redutase (NADPH2)/biossíntese , Pessoa de Meia-Idade , Fatores de Risco , Timidilato Sintase/biossíntese , Proteína Supressora de Tumor p53/biossíntese
11.
J Steroid Biochem Mol Biol ; 113(3-5): 202-8, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19159685

RESUMO

The human androgen receptor (AR) gene possesses two trinucleotide repeats of CAG and GGN in exon-1. The GGN repeat affects the amount of AR protein translated, while the CAG repeat affects the efficiency of AR transcriptionaly. In this study, we have genotyped these polymorphic tracts in a representative sample of 557 Caucasian adult individuals (314 women and 243 men) from the Canary Islands, Spain (the ENCA Study), and investigated their association with fasting serum levels of lipids, glucose and insulin. The number of CAG repeats in women (expressed as the average length of the two alleles) was inversely correlated with serum levels of LDL-cholesterol (Spearman rho=-0.179; P<0.01). Women with an average number of CAG repeats in the upper tertile showed significantly lower levels of LDL-cholesterol than those grouped in the lower and middle tertile, after adjusting for age, body mass index, waist-to-hip ratio, smoking and alcohol drinking. The number of GGN repeats in men was correlated with fasting insulin levels (Spearman rho=-0.206; P<0.01), the homeostasis model assessment of insulin resistance (HOMA-IR; Spearman rho=-0.230; P<0.01) and the McAuley index of insulin sensitivity (Spearman rho=0.194; P<0.01). Men with a number of GGN repeats in the upper tertile showed lower levels of insulin and HOMA and a higher level of the McAuley index than those grouped in the lower and middle tertile, after adjusting for the variables listed above. These results support the hypothesis that the longer alleles of the CAG and GGN polymorphisms in the exon-1 of the AR gene, indicative of lower androgenic signaling, respectively protect women from developing dyslipemia and men from developing insulin resistance.


Assuntos
Dislipidemias/genética , Éxons , Resistência à Insulina/genética , Polimorfismo Genético , Receptores Androgênicos/genética , Repetições de Trinucleotídeos , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Feminino , Predisposição Genética para Doença , Humanos , Masculino , Pessoa de Meia-Idade , Espanha , Adulto Jovem
12.
J Steroid Biochem Mol Biol ; 113(1-2): 85-91, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19095061

RESUMO

The exon 1 of the human androgen receptor (AR) gene contains two length polymorphisms of CAG (polyglutamine) and GGN (polyglycine). "In vitro" experiments suggest that the larger GGN repeats provide a lower AR-protein yield, whereas the larger CAG repeats decrease the AR transcriptional activity, both decreasing the AR signalling intensity. Here we have tested such possibilities in human prostatic cancer (CaP) specimens. We used 72 archival samples of radical prostatectomy. Parallel slides were used for AR protein or PSA immunohistochemistry, and for genotyping studies. Polymorphisms were genotyped by PCR, fragment length analysis and sequencing selected samples. The AR staining was positively correlated with the Gleason score (r=0.320; P=0.005), but it was not correlated to CAG or GGN repeat length or PSA staining. The number of GGN repeats was negatively correlated to the intensity of PSA staining (r=-0.243; P=0.04). Combination of short alleles of both tracts was significantly higher in: the heavier stained tertiles for PSA (P=0.03) and AR (P=0.06); and in the subgroup of samples having a Gleason score of 7 or higher (P=0.021). The results support the hypothesis that the shorter alleles of CAG and GGN repeats in the AR gene are associated to an increased AR signalling intensity in human prostate cancer, and with more aggressive forms of the disease.


Assuntos
Alelos , Éxons/genética , Antígeno Prostático Específico/metabolismo , Neoplasias da Próstata/genética , Receptores Androgênicos/genética , Coloração e Rotulagem , Expansão das Repetições de Trinucleotídeos/genética , Idoso , Estudos de Casos e Controles , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Estatísticas não Paramétricas
13.
Obesity (Silver Spring) ; 16(9): 2107-12, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18535544

RESUMO

There is evidence that androgens are regulators of insulin resistance (IR), and may be involved in the regulation of resistin, a cytokine that has been related with IR. Earlier studies found that androgen receptor length polymorphisms CAGn and GGNn and the aromatase polymorphism TTTAn may influence receptor or enzyme activity and serum concentrations of androgens. This study was designed to determine whether polymorphism length was related to serum resistin concentration and to other variables related with IR. In 1,580 persons chosen randomly from the general population of the Canary Islands (Spain), we measured polymorphism length, waist circumference, waist/hip ratio, BMI, and serum glucose concentration. In smaller subgroups, we also measured C-peptide (n = 677), resistin (n = 583), and leptin concentration (n = 754) and estimated IR (homeostasis model assessment-IR (HOMA2-IR)). In men, polymorphism length correlated with resistin concentration (CAGn, r = 0.13, P = 0.031; TTTAn, r = 0.15, P = 0.005; GGNn, r = -0.15, P = 0.026), and the correlations were confirmed in multivariate regression models. The length of CAGn and TTTAn correlated inversely with C-peptide (r = -0.13, P = 0.016 and r = -0.21, P < 0.001, respectively) and with estimated IR (r = -0.12, P = 0.032 and r = -0.19, P = 0.001, respectively). In men, length of the CAGn, GGNn, and TTTAn was associated with serum resistin concentration. These results support the hypothesis that androgens may be involved in the regulation of resistin. Resistin may be a link between IR and androgens.


Assuntos
Aromatase/genética , Receptores Androgênicos/genética , Resistina/sangue , Adolescente , Adulto , Idoso , Antropometria , Glicemia/metabolismo , Peptídeo C/sangue , Estudos de Coortes , Estudos Transversais , Feminino , Humanos , Resistência à Insulina/genética , Leptina/sangue , Masculino , Repetições de Microssatélites , Pessoa de Meia-Idade , Polimorfismo Genético , Adulto Jovem
14.
J Steroid Biochem Mol Biol ; 109(3-5): 336-43, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18430567

RESUMO

Steroid hormones activate target cells through specific receptors that discriminate among ligands based upon recognition of distinct structural features. For most known steroids, membrane and nuclear receptors co-exist in many target cells. However, while the structure of the nuclear receptors and their function as transcriptional activators of specific target genes is generally well understood, the identity of the membrane receptors remains elusive. Using pharmacological and biochemical approaches, we are beginning to characterize receptors for glucocorticoids and anabolic-androgenic steroids in male rat liver membranes. Male rat liver endoplasmic reticulum contains two steroid binding sites which are functionally related and associated with a 90-134 kDa oligomeric protein: (1) the low-affinity glucocorticoid binding site (LAGS), composed at least in part of two peptides (37 and 53 kDa) that bind glucocorticoids and (2) the stanozolol binding protein (STBP), composed at least in part of three peptides (22, 31, and 55 kDa) that bind the synthetic androgen stanozolol. These steroid binding proteins have many properties different from those of classical nuclear receptors, with the salient differences being a failure to recognize "classical" ligands for nuclear receptors together with marked differences in biochemical properties and physiological regulation. The mechanism of interaction of glucocorticoids with the LAGS can be clearly distinguished from that with STBP. Moreover, STBP shows an extremely narrow pharmacological profile, being selective for ST and its analog, danazol, among more than 100 steroids and non-steroidal compounds that were assayed, including those that are able to displace glucocorticoids from the LAGS. The level of LAGS activity undergoes dramatic variations following changes from the physiological serum levels of thyroid hormones, glucocorticoids, GH, vitamin A, and E2. However, neither thyroid hormones nor GH have a critical role on STBP activity. The STBP is functionally related to LAGS. We have suggested a novel mechanism for STBP whereby membrane-associated glucocorticoid binding activity is targeted by stanozolol (and 16beta-hydroxylated stanozolol): stanozolol modulates glucocorticoid activity in the liver through negative allosteric modulation of the LAGS resulting in an effective increase in classical GR-signaling by increasing glucocorticoid availability to the cytosolic GR.


Assuntos
Membrana Celular/metabolismo , Glucocorticoides/metabolismo , Hormônios Esteroides Gonadais/metabolismo , Fígado/citologia , Fígado/metabolismo , Hormônios Hipofisários/metabolismo , Animais , Sítios de Ligação
15.
Eur J Cancer ; 43(16): 2373-80, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17728127

RESUMO

The exon 1 of the human androgen receptor gene (AR) contains both CAG (polyglutamine) and GGN (polyglycine) repeat length polymorphisms. Large CAG repeats have been related to an increased risk of breast cancer (BC), whereas the influence of the GGN repeats is still unclear. Here, we have studied how the length of CAG and GGN repeats is associated with the risk of BC in a population from Tenerife (Canary Islands, Spain). The study was carried out on 257 woman diagnosed with BC and 393 controls, nesting in the 'CDC of the Canary Islands' cohort study. The AR CAG and GGN genotyping was performed by means of PCR amplification with specific fluorescently labelled primers followed by a capillary electrophoresis. The allelic distribution of CAG and GGN polymorphisms was similar in cases and controls. The mean of short and long CAG and GGN alleles did not show differences between cases and controls and the same was true when the average length of both CAG alleles (CAG(n)) and GGN alleles (GGN(n)) was considered. However, when CAG(n) and GGN(n) were categorised using 22 and 24 repeats as the cut-off point, respectively, significant differences between cases and controls were observed. The CAG(n)>22 repeats were more frequent in cases than in controls, being associated with an increased risk of BC (OR=1.49; CI(95%)=1.06-2.09; p=0.021). No significant differences were found for categorised GGN(n). For CAG(n)/GGN(n) combinations, the highest BC risk was found to be associated with the CAG(n)>22/GGN(n)24 combination (OR=2.47; CI(95%)=1.37-4.46; p=0.003). In conclusion, our results indicate that longer CAG(n)/GGN(n) combinations increase the risk of BC and suggest that CAG and GGN AR polymorphisms should be considered in order to assess the BC risk.


Assuntos
Neoplasias da Mama/genética , Genes BRCA1/fisiologia , Genes BRCA2/fisiologia , Polimorfismo Genético/genética , Receptores Androgênicos/genética , Adulto , Idoso , Alelos , Estudos de Casos e Controles , Estudos de Coortes , Feminino , Predisposição Genética para Doença , Humanos , Pessoa de Meia-Idade , Fatores de Risco
16.
J Steroid Biochem Mol Biol ; 105(1-5): 1-15, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17631997

RESUMO

Aromatase (CYP19) converts adrenal and ovarian androgens into estrogens, which supports the growth of estrogen-dependent breast cancers. Anti-aromatase agents are displacing antiestrogens as the first-line treatment for estrogen receptor positive breast cancers. Androgens can act as estrogen precursors, but besides this capability they can also directly act on breast cancer cells by binding to androgen receptors, which are present in the majority of breast cancer specimens. Epidemiological and clinical evidences suggest that higher levels of circulating androgen increase the risk of developing breast cancer. Androgen receptor gene polymorphisms which render the more transcriptionally active receptors have been related to a lower risk of breast cancer. It is currently accepted that androgens act as antiproliferative agents in the presence of estrogens in some breast cancer cell lines. However, emerging evidence suggests that direct androgenic activity might also stimulate cell growth in a subset of estrogen-resistant breast tumors. Here we discuss the supporting evidence which proposes that androgens themselves are actively involved in breast carcinogenesis and its clinical behaviour.


Assuntos
Androgênios/fisiologia , Neoplasias da Mama/fisiopatologia , Receptores Androgênicos/fisiologia , Progressão da Doença , Humanos , Polimorfismo Genético , Receptores Androgênicos/genética , Medição de Risco
17.
Int J Cancer ; 119(3): 563-70, 2006 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-16506206

RESUMO

Microsatellite instability (MSI) and mutations in the PTEN gene are among the molecular alterations involved in endometrial carcinogenesis. There is conflicting information regarding to their role in this type of tumor. For this reason, we have studied both molecular lesions in a large population-based series of 205 patients with sporadic endometrial cancer. MSI was found in 41 (20.0%) of the tumors and PTEN mutations were found in 74 (36.1%). There were differences in genotype between tumors with and without MSI. Tumors with MSI showed both a higher frequency of PTEN mutations (58.5% vs. 30.4%) (p=0.002, Fisher's exact test) and a higher number of insertions or deletions (I/D) of one nucleotide within the mononucleotide tracts of the PTEN gene (45.8% vs. 11.4% out of all I/D, p=0.005). Conversely, G:C to A:T transitions in CpG dinucleotides were found mostly in microsatellite stable tumors (57.7% vs. 18.2% out of all single-base substitutions, p=0.037). Overall, 67.6% of tumors with mutated PTEN exhibited multiple mutations or allelic imbalance (AI). Multiple PTEN mutations in the same tumor were more frequent in tumors with MSI (60% vs. 25.7%); by contrast the presence of AI accompanying PTEN mutation was higher in microsatellite stable tumors (74.3% vs. 40%) (p=0.028). In addition, patients with both genetic alterations were diagnosed at more advanced stage of progression (54.2% for MSI vs. 20.0% for MSS, p=0.006), and exhibited a worse prognosis (hazard ratio [95% confidence interval]: 3.0 [1.1-13.1], p=0.034, log-rank test) than patients with only the PTEN gene mutated. Our data suggest that the DNA mismatch repair system status influences: (i) both the frequency and the mutational spectrum of PTEN; (ii) the nature of one of the hits that inactivate this tumor-suppressor gene; and (iii) the clinical condition and behavior of the patients.


Assuntos
Neoplasias do Endométrio/patologia , Repetições de Microssatélites/genética , Mutação , PTEN Fosfo-Hidrolase/genética , Idoso , Neoplasias do Endométrio/genética , Feminino , Frequência do Gene , Genótipo , Humanos , Perda de Heterozigosidade , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Análise de Sobrevida
18.
Int J Cancer ; 118(6): 1420-5, 2006 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-16187285

RESUMO

The human androgen receptor (AR) gene possesses 2 trinucleotide repeats of CAG and GGN in exon 1. The CAG repeat corresponds to a polyglutamine tract in the N-terminal region of the receptor, that affects its transcriptional efficiency. The GGN repeat codifies for a polyglycine tract, and affects the amount of the AR protein transcribed. The endometrium contains ARs and the androgens have antiproliferative properties in cultured endometrial cancer (EC) cells. Larger CAG repeats of the AR gene give rise to a weaker transcriptional activity and have been found to be associated with endometrial carcinogenesis. The possible involvement of CAG and GGN tracts in the progression of EC is unknown. To study that possibility, we have genotyped both CAG and GGN polymorphisms of the AR gene in tumor tissue genomic DNA from a series of 204 consecutive patients with EC, and analyzed the results with regard to the pathological features and clinical outcome of patients. We classified the alleles as S (short median). The genotype with both S-CAG repeat alleles (SS-CAG) was more common in patients diagnosed at an early stage (41.6% SS-CAG vs 22.6% SL- and LL-CAG together, p = 0.048) and in tumors that did not invade the vascular space (43.0% SS-CAG vs 26.4% SL- and LL-CAG together, p = 0.034). The genotype with SS-GGN alleles was more common in well-differentiated tumors (41.2% SS-GGN vs 25.2% LS- and LL-GGN together, p = 0.017) and in endometrioid histological subtype tumors (35.3% SS-GGN vs 13.0% SL- and LL-GGN together, p = 0.034). When the genotypes of both repeats coexisting in each tumor specimen were taken into consideration, the relationship between the SS-CAG genotype and early stage remained only in the presence of the SS-GGN genotype (43.9% vs 0%, p = 0.01). No other associations were observed. In univariate survival analysis, patients with short alleles of both repeats (SS-CAG and SS-GGN genotypes simultaneously) had a lower risk of cancer-specific death (p = 0.032, mean follow-up: 63 months). Our data suggests that short CAG or GGN repeats of the AR gene are associated with a more benign condition of traditional prognostic variables in EC.


Assuntos
Neoplasias do Endométrio/patologia , Polimorfismo Genético , Receptores Androgênicos/genética , Expansão das Repetições de Trinucleotídeos/genética , Repetições de Trinucleotídeos/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Alelos , Neoplasias do Endométrio/genética , Feminino , Frequência do Gene , Genótipo , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Retrospectivos , Análise de Sequência de DNA/métodos
19.
J Steroid Biochem Mol Biol ; 84(2-3): 245-53, 2003 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-12711010

RESUMO

Steroid-binding proteins unrelated to the classical nuclear receptors have been proposed to play a role in non-genomic effects of steroid hormones. We have previously described that the low-affinity glucocorticoid binding protein (LAGS), present in the endoplasmic reticulum of the male rat liver, has pharmacological and biochemical properties different from those of nuclear receptors. The LAGS is under multihormonal regulation and binds glucocorticoids, progestins, and synthetic steroids but is unable to bind either estradiol, testosterone, or triamcinolone acetonide. In this study, we have solubilized the LAGS and investigated their pharmacological and hydrodynamic properties and their peptide composition. We found that LAGS is an integral protein bound to the endoplasmic reticulum. CHAPS provided its optimal solubilization without changes in its pharmacological properties. Hydrodynamic properties of LAGS showed that it has a molecular mass of at least 135 kDa. SDS-PAGE of covalently-labeled LAGS showed that [3H]dexamethasone binds two peptides of 53 and 37 kDa, respectively. Thus, the LAGS appears as an oligomeric protein under multihormonal regulation. The availability of solubilized LAGS and the fact that it can be induced in vivo represent major steps toward purification and understanding the functional significance of this unique steroid-binding protein.


Assuntos
Retículo Endoplasmático/metabolismo , Luz , Fígado/metabolismo , Animais , Membrana Celular/metabolismo , Centrifugação com Gradiente de Concentração , Cromatografia em Gel , Detergentes/farmacologia , Dexametasona/farmacologia , Relação Dose-Resposta a Droga , Eletroforese em Gel de Poliacrilamida , Estradiol/metabolismo , Glucocorticoides/metabolismo , Microssomos Hepáticos/metabolismo , Octoxinol , Peptídeos/química , Polietilenoglicóis/farmacologia , Progestinas/metabolismo , Ligação Proteica , Ensaio Radioligante , Ratos , Ratos Sprague-Dawley , Esteroides/metabolismo , Frações Subcelulares/metabolismo , Testosterona/metabolismo , Fatores de Tempo , Triancinolona Acetonida/metabolismo , Água
20.
JPEN J Parenter Enteral Nutr ; 25(6): 338-45, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11688939

RESUMO

BACKGROUND: Apoptosis is a programmed cell death, genetically controlled, that can be activated by physiological and pathophysiological events and by the administration of several drugs, including the exogenous administration of corticosteroids. The aim of this study was to develop a rat model of intestinal lymphocytic apoptosis induced by dexamethasone to determine if apoptosis could be prevented by enteral or parenteral nutrition. METHODS: Male Sprague-Dawley rats were used. On day 0, the right internal jugular vein was catheterized for parenteral nutrition, and a silicone tube was inserted into the duodenum for enteral feeding. Animals (n = 6/group) were randomly assigned to one of the following 3 feeding regimens: an immune-enhancing enteral diet; its placebo (the same formula without immunonutrients); and isocaloric isonitrogenous parenteral nutrition. On the seventh day, 200 microg of dexamethasone or vehicle were administered by i.v. bolus, and the diets were continued for 1 more day. Intestinal Peyer patches and thymic lymphocytic apoptosis were determined both by flow-cytometry and immunohistochemistry. RESULTS: A single dexamethasone dose (200 microg/rat) administered to surgically treated rats fasted for 18 hours, 24 hours later, caused massive intestinal and Peyer patches lymphocytic apoptosis (96 +/- 2% and 85 +/- 5%, respectively; p < .0001 versus vehicle in both kinds of tissue). Lymphocytic apoptosis was reduced to almost indetectable levels in intestinal and lamina propia lymphocytes (from 96 +/- 2% to <0.6%; p < .0001). Peyer patches lymphocytic apoptosis was reduced as well (from 85 +/- 5% to 15 +/- 7.1%; p < .001) in animals prefed the 2 enteral nutrition formulas. Those prefed parenteral nutrition only showed a partial decrease of lymphocytic apoptosis in the intestine (from 96 +/- 2% to 53 +/- 23%; p < .001). Nutrition had no effect on the dexamethasone-induced thymus involution. CONCLUSIONS: Enteral nutrition prevents intestinal intraepithelial and lamina propia lymphocytic apoptosis due to dexamethasone. These findings support the use of early enteral nutrition in critically ill patients treated with corticosteroids.


Assuntos
Apoptose/efeitos dos fármacos , Dexametasona/toxicidade , Nutrição Enteral , Glucocorticoides/toxicidade , Mucosa Intestinal/imunologia , Linfócitos/efeitos dos fármacos , Nódulos Linfáticos Agregados/imunologia , Animais , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Citometria de Fluxo , Imuno-Histoquímica , Mucosa Intestinal/patologia , Masculino , Nutrição Parenteral , Nódulos Linfáticos Agregados/patologia , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley
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