RESUMEN
Interferon regulatory factor 5 (IRF5) regulates type I interferon (IFN)-responsive genes, and has been one of the most consistently associated genes with systemic lupus erythematosus (SLE). We sought to investigate whether IRF5 haplotypes are associated with risk for SLE in the genetically homogeneous Greek population of the island of Crete, as well as whether these haplotypes are associated with increased type I IFN. 322 SLE patients and 247 healthy controls from Crete were genotyped for rs2004640, rs3807306, rs10488631 and rs2280714 SNPs of IRF5 gene by using Taqman primer-probe sets. Type I IFN levels were measured using a functional reporter cell assay. All IRF5 SNPs examined were found to be associated with SLE in univariate case-control analysis. The 4 SNPs formed 5 major haplotypes and the Neanderthal-derived TACA risk haplotype was present in Crete and enriched in the SLE cases (OR=2.01, P=0.0003). Serum IFN levels were measured in a subset of the SLE patients, and carriage of the TACA haplotype was associated with higher circulating type I IFN levels (P=0.037). This study demonstrates the association of IRF5 with an increased susceptibility for SLE in the population of Crete and emphasizes the association of the Neanderthal-derived IRF5 haplotype with SLE susceptibility. Patients carrying allele the Neanderthal allele C had greater type I IFN, supporting a functional consequence of this polymorphism.
Asunto(s)
Predisposición Genética a la Enfermedad , Factores Reguladores del Interferón/genética , Lupus Eritematoso Sistémico/genética , Adulto , Animales , Estudios de Casos y Controles , Femenino , Grecia , Haplotipos , Humanos , Interferón Tipo I/sangre , Interferón Tipo I/inmunología , Lupus Eritematoso Sistémico/inmunología , Masculino , Persona de Mediana Edad , Hombre de Neandertal/genéticaRESUMEN
OBJECTIVES: Several rheumatoid arthritis (RA) susceptibility loci have also been found to be associated with psoriatic arthritis (PsA), demonstrating that there is a degree of genetic overlap between various autoimmune diseases. We sought to investigate whether single nucleotide polymorphisms (SNPs) mapping to previously reported RA and/or PsA susceptibility loci, including PLCL2, CCL21, REL, STAT4, CD226, PTPN22, and TYK2, are associated with risk for the two diseases in a genetically homogeneous Greek population. METHOD: This study included 392 RA patients, 126 PsA patients, and 521 healthy age- and sex-matched controls from Greece. Genotyping of the SNPs was performed with Taqman primer/probe sets. Bioinformatic analysis was performed using BlastP, PyMOL, and Maestro and Desmond. RESULTS: A significant association was detected between the GC genotype of rs34536443 (TYK2) in both the PsA and RA cohorts. The C allele of this SNP was associated with PsA only. Evidence for association with PsA was also found for the GG genotype and G allele of the rs10181656 SNP of STAT4. The TC genotype of the rs763361 SNP of CD226 was associated with PsA only. CONCLUSIONS: Genetic overlap between PsA and RA was detected for the rs34536443 SNP of the TYK2 gene within a Greek population. An association of STAT4 (rs10181656) with PsA was confirmed whereas CD226 (rs763361) was associated with PsA but not with RA, in contrast to previous reports. The different findings of this study compared to previous ones highlights the importance of comparative studies that include various ethnic or racial populations.
Asunto(s)
Artritis Psoriásica/genética , Artritis Reumatoide/genética , Población Blanca/genética , Adulto , Anciano , Alelos , Antígenos de Diferenciación de Linfocitos T/genética , Estudios de Casos y Controles , Quimiocina CCL21/genética , Estudios de Cohortes , Femenino , Predisposición Genética a la Enfermedad , Genotipo , Técnicas de Genotipaje , Grecia , Humanos , Péptidos y Proteínas de Señalización Intracelular/genética , Masculino , Persona de Mediana Edad , Modelos Moleculares , Proteínas Oncogénicas v-rel/genética , Polimorfismo de Nucleótido Simple , Proteína Tirosina Fosfatasa no Receptora Tipo 22/genética , Factor de Transcripción STAT4/genética , TYK2 Quinasa/genéticaRESUMEN
BACKGROUND: Juvenile idiopathic arthritis (JIA) is an autoimmune disease characterized by persistent chronic arthritis. Disease risk is believed to be influenced by both genetic and environmental factors. It is well established that the PTPN22 single nucleotide polymorphism (SNP) rs2476601 is associated with JIA susceptibility. It was recently reported in an Australian study that this association is restricted to females and is not observed in males. A significant source of inconsistency amongst the literature on autoimmune disease susceptibility genes stems from an inability to replicate genetic findings across different racial or ethnic groups. We therefore attempted to generate further evidence of the female-specific association of rs2476601 in a homogeneous Greek population. FINDINGS: We genotyped rs2476601 in 128 Caucasian JIA patients (70.3 % female) and 221 healthy controls (28.1 % female) from Northern Greece. Overall, PTPN22 was associated with increased risk of JIA in this Greek sample (OR = 2.3, 95 % CI 1.1 - 5.1, p = 0.038). Sex-stratified analyses showed that, once again, the risk association was restricted to females (Female: OR = 19.9, 95 % CI 1.2 - 342, p = 0.0016; Male: OR = 1.1, 95 % CI 0.3 - 3.1, p = 0.94) supporting the prior findings. CONCLUSIONS: Our data demonstrates that this sex-specific pattern of association is broadly applicable to different populations, and provides further impetus to undertake mechanistic studies to understand the impact of sex on PTPN22 in JIA.
Asunto(s)
Artritis Juvenil/genética , ADN/genética , Predisposición Genética a la Enfermedad , Polimorfismo Genético , Proteína Tirosina Fosfatasa no Receptora Tipo 22/genética , Alelos , Artritis Juvenil/epidemiología , Artritis Juvenil/metabolismo , Femenino , Frecuencia de los Genes , Genotipo , Grecia/epidemiología , Humanos , Incidencia , Masculino , Proteína Tirosina Fosfatasa no Receptora Tipo 22/metabolismo , Estudios Retrospectivos , Factores de Riesgo , Factores SexualesRESUMEN
Alleles of interferon (IFN) regulatory factor 8 (IRF8) are associated with susceptibility to both systemic lupus erythematosus (SLE) and multiple sclerosis (MS). Although high-type I IFN is thought to be causal in SLE, type I IFN is used as a therapy in MS. We investigated whether IRF8 alleles were associated with type I IFN levels or serologic profiles in SLE and MS. Alleles that have been previously associated with SLE or MS were genotyped in SLE and MS patients. The MS-associated rs17445836G allele was associated with anti-double-stranded DNA (dsDNA) autoantibodies in SLE patients (meta-analysis odds ratio=1.92). The same allele was associated with decreased serum IFN activity in SLE patients with anti-dsDNA antibodies, and with decreased type I IFN-induced gene expression in peripheral blood mononuclear cell from anti-dsDNA-negative SLE patients. In secondary progressive MS patients, rs17445836G was associated with decreased serum type I IFN. Rs17445836G was associated with increased IRF8 expression in SLE patient B cells. In summary, IRF8 rs17445836G is associated with human autoimmune disease characterized by low-type I IFN levels, and this may have pharmacogenetic relevance as type I IFN is modulated in SLE and MS. The association with autoantibodies and increased IRF8 expression in B cells supports a role for rs17445836G in humoral tolerance.
Asunto(s)
Factores Reguladores del Interferón/genética , Interferón Tipo I/sangre , Lupus Eritematoso Sistémico/genética , Esclerosis Múltiple/genética , Polimorfismo de Nucleótido Simple , Autoanticuerpos/inmunología , Estudios de Casos y Controles , ADN/inmunología , Humanos , Lupus Eritematoso Sistémico/sangre , Lupus Eritematoso Sistémico/inmunología , Esclerosis Múltiple/sangre , Esclerosis Múltiple/inmunologíaRESUMEN
The strategy of studying the putative role of RA susceptibility genetic factors in the development of juvenile idiopathic arthritis (JIA), an autoimmune disease characterized by persistent chronic arthritis, has been proven highly successful so far. Moreover, accumulated evidence indicates that an ethnic heterogeneity of genetic factors exists for rheumatic disorders. We investigated whether five single nucleotide polymorphisms (SNPs), previously found to be associated with JIA in various populations so far, are also associated with JIA in Greece. The sample set consisted of 128 Caucasian JIA patients and 221 healthy controls from Northern Greece. Five Single Nucleotide Polymorphisms (SNPs) markers, namely TRAF1/C5 rs10818488, PTPN22 rs2476601, STAT4 rs7574865, CD247 rs1773560 and PTPN2 rs7234029 SNPs were genotyped in a case-control study with Restriction Fragment Length Polymorphisms (RFLPs) or Taqman primer-probe sets. This study demonstrated for the first time in a Greek population that the PTPN22, TRAF1/C5 and CD247 polymorphisms examined are associated with an increased susceptibility to JIA, thus suggesting that the respective risk alleles may confer susceptibility to clinically distinct disorders. However, our results did not demonstrate any association of STAT4 and PTPN2 SNPs with the disease in our population, thus highlighting the importance of comparative studies in different ethnic populations.
Asunto(s)
Artritis Juvenil/genética , Sitios Genéticos/genética , Predisposición Genética a la Enfermedad , Adolescente , Adulto , Alelos , Complejo CD3/genética , Niño , Etnicidad/genética , Femenino , Estudios de Asociación Genética , Grecia , Humanos , Masculino , Polimorfismo de Nucleótido Simple , Proteína Tirosina Fosfatasa no Receptora Tipo 2/genética , Proteína Tirosina Fosfatasa no Receptora Tipo 22/genética , Factor de Transcripción STAT4/genética , Factor 1 Asociado a Receptor de TNF/genética , Adulto JovenRESUMEN
Diverse vanadium biological activities entail complex interactions with physiological target ligands in aqueous media and constitute the crux of the undertaken investigation at the synthetic level. Facile aqueous redox reactions, as well as nonredox reactions, of V(III) and V(V) with physiological citric acid and hydrogen peroxide, under pH-specific conditions, led to the synthesis and isolation of a well-formed crystalline material upon the addition of ethanol as the precipitating solvent. Elemental analysis pointed to the molecular formulation (NH4)4[(VO2){VO(O2)}(C6H5O7)2]·1.5H2O (1). Complex 1 was further characterized by Fourier transform infrared (FT-IR) spectroscopy, nuclear magnetic resonance (NMR), Raman spectroscopy, cyclic voltammetry, and X-ray crystallography. The crystallographic structure of 1 reveals the presence of the first dinuclear V(V)-citrate complex with non-peroxo- and peroxo-containing V(V) ions, concurrently present within the basic VV2O2 core. The nonperoxo unit VO2+ and the peroxo unit VO(O2)+ are each coordinated to a triply deprotonated citrate ligand in a distinct coordination mode and coordination geometry around the V(V) ions. These units are similar to those in homodinuclear complexes bearing oxo or peroxo groups. The unique assembly of both units in the anion of 1 renders the latter as a potential intermediate in the peroxidation process, from [V2O4(C6H5O7)2]4 to [V2O2(O2)2(C6H6O7)2]2. The transformation reactions of 1 establish its connection with several V(V) and V(IV) dinuclear species present in the aqueous distribution of the V(IV,V)-citrate systems. The shown position of 1 as an intermediate in the mechanism of H2O2 addition to dinuclear V(V)-citrate species portends its role in the complex aqueous distribution of species in the ternary V(V)-peroxo-citrate system and its potential reactivity in (bio)chemically relevant media.
Asunto(s)
Ácido Cítrico/química , Peróxido de Hidrógeno/química , Compuestos Organometálicos/química , Peróxidos/química , Vanadio/química , Cristalografía por Rayos X , Espectroscopía de Resonancia Magnética , Modelos Moleculares , Espectroscopía Infrarroja por Transformada de Fourier , Espectrometría Raman , Agua/químicaRESUMEN
Autoimmune diseases affect approximately 5% of the population, but much work remains to define the genetic risk factors and pathogenic mechanisms underlying these conditions. There is accumulating evidence that common genetic factors might predispose to multiple autoimmune disorders. Systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA) are complex autoimmune disorders with multiple susceptibility genes. The functional R620W (C1858T) polymorphism of the protein tyrosine phosphatase non-receptor type 22 (PTPN22) gene, a member of the PTPs that negatively regulate T-cell activation, has been recently associated with susceptibility to various autoimmune diseases. The aim of this study was to assess whether the C1858T polymorphism of PTPN22 also confers increased risk for SLE and RA in the genetically homogeneous population of Crete. It was found that the minor T allele of the PTPN22 C1858T SNP was more common in SLE patients than in control individuals (odds ratio [OR] = 1.91, 95% confidence interval [CI] = 1.11 to 3.9, p = 0.017). No significant difference was observed in the frequency of this allele when RA patients were compared with controls (OR = 1.14, 95% CI = 0.65 to 1.9, p = 0.64). Although the PTPN22 1858 T allele is found at decreased frequency in Southern Europe, including Crete, an association was found between this allele and SLE in the population studied.
Asunto(s)
Artritis Reumatoide/genética , Lupus Eritematoso Sistémico/genética , Proteína Tirosina Fosfatasa no Receptora Tipo 22/genética , Adulto , Estudios de Casos y Controles , Femenino , Predisposición Genética a la Enfermedad , Grecia , Humanos , Masculino , Persona de Mediana Edad , Polimorfismo de Nucleótido SimpleRESUMEN
Efforts to delineate the interactions of neurotoxic Al(III) with low molecular mass substrates relevant to neurodegenerative processes, led to the investigation of the pH-specific synthetic chemistry of the binary Al(III)-[N-(phosphonomethyl) iminodiacetic acid] (Al-NTAP), Al(III)-[nitrilo-tris(methylene-phosphonic acid)] (Al-NTA3P), and Al(III)-[1-hydroxy ethylidene-1,1-diphosphonic acid] (Al-HEDP) systems, in correlation with solution speciation studies. Reaction of Al(NO(3))(3).9H(2)O with NTAP at pH 7.0 and 4.0 afforded the new species (CH(6)N(3))(4)[Al(2)(C(5)H(6)NPO(7))(2)(OH)(2)].8H(2)O (1) and (NH(4))(2)[Al(2)(C(5)H(6)NPO(7))(2)(H(2)O)(2)].4H(2)O (2), while reaction of Al(NO(3))(3).9H(2)O with NTA3P led to K(8)[Al(2)(C(3)H(6)NP(3)O(9))(2)(OH)(2)].20H(2)O (3). Complexes 1-3 were characterized by elemental analysis, FT-IR, (13)C, (31)P, (1)H NMR (for 1-2 solid state and solution NMR where feasible), and X-ray crystallography. The structures of 1-3 reveal the presence of uniquely defined dinuclear complexes of octahedral Al(III) bound to fully deprotonated phosphonate ligands, water and hydroxo moieties. The aqueous solution speciation studies on the aforementioned binary systems project a clear picture of the binary Al(III)-(carboxy)phosphonate interactions and species under variable pH-conditions and specific Al(III):ligand stoichiometry. The concurrent solid state and solution work (a) exemplifies essential structural and chemical attributes of soluble aqueous species, reflecting well-defined interactions of Al(III) with phosphosubstrates and (b) strengthens the potential linkage of neurotoxic Al(III) chemical reactivity toward O,N-containing (carboxy)phosphate-rich cellular targets.
Asunto(s)
Aluminio/toxicidad , Neuronas/efectos de los fármacos , Organofosfonatos/toxicidad , Aluminio/química , Cristalografía por Rayos X , Ácido Etidrónico/síntesis química , Ácido Etidrónico/química , Humanos , Iminoácidos/química , Ligandos , Espectroscopía de Resonancia Magnética , Enfermedades Neurodegenerativas/inducido químicamente , Organofosfonatos/químicaRESUMEN
Vanadium participation in cellular events entails in-depth comprehension of its soluble and bioavailable forms bearing physiological ligands in aqueous distributions of binary and ternary systems. Poised to understand the ternary V(V)-H(2)O(2)-amino acid interactions relevant to that metal ion's biological role, we have launched synthetic efforts involving the physiological ligands glycine and H(2)O(2). In a pH-specific fashion, V(2)O(5), glycine, and H(2)O(2) reacted and afforded the unusual complexes (H(3)O)(2)[V(2)(O)(2)(mu(2):eta(2):eta(1)-O(2))(2)(eta(2)-O(2))(2)(C(2)H(5)NO(2))] x 5/4 H(2)O (1) and K(2)[V(2)(O)(2)(mu(2):eta(2):eta(1)-O(2))(2)(eta(2)-O(2))(2)(C(2)H(5)NO(2))] x H(2)O (2). 1 crystallizes in the triclinic space group P1, with a = 7.805(4) A, b = 8.134(5) A, c = 12.010(7) A, alpha = 72.298(9) degrees, beta = 72.991(9) degrees, gamma = 64.111(9) degrees, V = 641.9(6) A(3), and Z = 2. 2 crystallizes in the triclinic space group P1, with a = 7.6766(9) A, b = 7.9534(9) A, c = 11.7494(13) A, alpha = 71.768(2) degrees, beta = 73.233(2) degrees, gamma = 65.660(2) degrees, V = 610.15(12) A(3), and Z = 2. Both complexes 1 and 2 were characterized by UV/visible, LC-MS, FT-IR, Raman, NMR spectroscopy, cyclic voltammetry, and X-ray crystallography. The structures of 1 and 2 reveal the presence of unusual ternary dinuclear vanadium-tetraperoxo-glycine complexes containing [(V(V)=O)(O(2))(2)](-) units interacting through long V-O bonds and an effective glycinate bridge. The latter ligand is present in the dianionic assembly as a bidentate moiety spanning both V(V) centers in a zwitterionic form. The collective physicochemical properties of the two ternary species 1 and 2 project the chemical role of the low molecular mass biosubstrate glycine in binding V(V)-diperoxo units, thereby stabilizing a dinuclear V(V)-tetraperoxo dianion. Structural comparisons of the anions in 1 and 2 with other known dinuclear V(V)-tetraperoxo binary anionic species provide insight into the chemical reactivity of V(V)-diperoxo species in key cellular events such as insulin mimesis and antitumorigenicity, potentially modulated by the presence of glycinate and hydrogen peroxide.
Asunto(s)
Glicina/química , Compuestos Organometálicos/síntesis química , Vanadatos/química , Cristalografía por Rayos X , Electroquímica , Espectroscopía de Resonancia Magnética , Compuestos Organometálicos/química , Compuestos Organometálicos/aislamiento & purificación , Espectrofotometría Ultravioleta , Espectroscopía Infrarroja por Transformada de Fourier , Espectrometría RamanRESUMEN
OBJECTIVES: To describe the concentrations of sTREM-1 in patients with sepsis and to explore the effects of their serum on the expression of TREM-1 on U937 monocytes. METHODS: Blood was sampled at regular time intervals in 56 patients with sepsis. Concentrations of tumour necrosis factor-alpha (TNFalpha), interleukin-1beta (IL-1alpha), IL-6, IL-8, IL-10 and IL-12p70 and sTREM-1 were measured. U937 monocytes were incubated in the presence of serum at sepsis onset. RESULTS: Median sTREM-1 concentration on day 1 for patients with septic shock was 915 pg/ml and 228.5 pg/ml for those without shock (p = 0.002). TNFalpha, IL-1alpha, IL-6, IL-8 and IL-10 did not differ between them. A positive correlation was found between changes of sTREM-1 and SOFA scores from day 1 to 7. Sera of patients with septic shock evoked a significant increase of the expression of TREM-1. The concentrations of TNFalpha and IL-8 in supernatants increased only after stimulating with sera of patients without shock, but not after stimulating with sera of patients with shock. CONCLUSIONS: Levels of sTREM-1 correlated with sepsis severity. sTREM-1 is considerably higher in patients with shock compared to patients without shock. The serum of shocked patients could stimulate the expression of TREM-1 on U937 monocytes.
Asunto(s)
Glicoproteínas de Membrana/metabolismo , Monocitos/metabolismo , Receptores Inmunológicos/metabolismo , Choque Séptico , Adulto , Anciano , Anciano de 80 o más Años , Línea Celular , Citocinas/inmunología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Monocitos/citología , Índice de Severidad de la Enfermedad , Choque Séptico/sangre , Choque Séptico/inmunología , Receptor Activador Expresado en Células Mieloides 1RESUMEN
Increased frequency of microsatellite DNA instability (MSI) has been detected in the sputum of chronic obstructive pulmonary disease (COPD) patients. The aim of the present study was to investigate the relationship between MSI in sputum cells and exacerbation frequency, which is an important parameter in the clinical course of the disease. Induced sputum samples and peripheral blood obtained from 36 patients with COPD at stable state were analysed. The control group consisted of 30 nonsmoking healthy subjects. DNA was extracted and analysed for MSI using the following microsatellite markers: RH70958, D5S207, D6S2223, D6S344, D6S263, G29802, D13S71, D14S588, D14S292 and D17S250. Following MSI analysis, exacerbations were recorded for 3 yrs in total. No MSI was detected in healthy nonsmokers. A total of 18 (50%) out of 36 patients exhibited MSI in their sputum cells. Patients who exhibited MSI showed significantly increased frequency of exacerbations compared with patients that did not. In addition, a significantly increased frequency of purulent and of severe type exacerbations was found in patients exhibiting MSI. Patients positive for marker G29802, D13S71 or D14S588 presented increased exacerbation frequency. The significant association between microsatellite DNA instability and chronic obstructive pulmonary disease exacerbations indicates that somatic mutations could be involved in the pathogenesis and natural history of the disease.
Asunto(s)
Inestabilidad de Microsatélites , Enfermedad Pulmonar Obstructiva Crónica/genética , Fumar/efectos adversos , Esputo/citología , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Enfermedad Pulmonar Obstructiva Crónica/fisiopatología , Índice de Severidad de la Enfermedad , Fumar/genéticaRESUMEN
Distinguishing malignant from benign pleural effusions using routine cytology is a common diagnostic problem. Recently, genetic alterations, including microsatellite instability (MSI) and loss of heterozygosity (LOH), have been described in malignant pleural effusions and proposed as methods improving diagnostics. The purpose of this study was to evaluate a panel of molecular markers for the detection of genetic alterations of cells in pleural effusions and to determine their diagnostic value as an additional test to cytologic examination. Pleural fluid and peripheral blood from 48 patients (36 male and 12 female, median age 71 years) were analyzed. Twenty-six patients had malignant pleural effusion, including 23 lung cancer and three metastatic non-pulmonary carcinoma. The control group consisted of 22 patients with benign pleural effusions. Only 14 malignancy-associated pleural effusions were cytology-positive for malignant cells (54%), whereas all benign pleural effusions were negative. DNA was extracted from all the samples and analysed for MSI and/or LOH using the following microsatellite markers: D3S1234, D9S171, D12S363, D17S250, D5S346 and TP53Alu, located at five chromosomal regions: 3p, 9p, 12q, 17q, 5q. Microsatellite analysis of the pleural fluid pellet exhibited genetic alterations in two neoplastic pleural fluid cases and in one inflammatory case. Two out of 26 (7.6%) patients with malignant pleural effusion showed genetic alterations. One exhibited MSI in three different microsatellite markers (D17S250, D9S171, D3S134) and the other showed LOH in marker D3S134. One out of 22 (4.5%) patients with benign pleural effusion showed LOH in marker D3S134. In conclusion, genetic alterations at the level of microsatellite DNA, were detected only in very few cases of malignant pleural effusions, and in one case of benign pleural effusion. Thus, our data suggest that microsatellite DNA analysis does not facilitate the diagnosis of malignant pleural effusion.
Asunto(s)
ADN de Neoplasias/genética , ADN/genética , Repeticiones de Microsatélite , Derrame Pleural/fisiopatología , Neoplasias Pleurales/fisiopatología , Anciano , Anciano de 80 o más Años , Mapeo Cromosómico , Cromosomas Humanos , Femenino , Inestabilidad Genómica , Humanos , L-Lactato Deshidrogenasa/análisis , Masculino , Persona de Mediana Edad , Proteínas de Neoplasias/análisis , Proteínas/análisisAsunto(s)
Dependencia de Heroína/complicaciones , Edema Pulmonar/etiología , Rabdomiólisis/inducido químicamente , Adulto , Aneurisma/complicaciones , Aneurisma/diagnóstico por imagen , Angiografía , Insuficiencia Cardíaca/etiología , Insuficiencia Cardíaca/cirugía , Humanos , Masculino , Arteria Renal/diagnóstico por imagen , Disfunción Ventricular Izquierda/inducido químicamente , Disfunción Ventricular Izquierda/complicacionesRESUMEN
Previous studies have shown that microsatellite (MS) DNA instability (MSI) is detectable in sputum cells in chronic obstructive pulmonary disease (COPD) and asthma. The aim of the present study was to investigate whether asthma and COPD could be distinguished at the MS DNA level. DNA was extracted from sputum cells and white blood cells from 63 COPD patients, 60 non-COPD smokers, 36 asthmatics and 30 healthy nonsmokers. Ten MS markers located on chromosomes 2p, 5q, 6p, 10q, 13q, 14q and 17q were analysed. No MSI was detected in non-COPD smokers or healthy nonsmokers. A significantly higher proportion of COPD patients exhibited MSI (49.2%) compared to asthmatics (22.2%). MSI was detected even in the mild stages of COPD (33.3%) and asthma (22.2%). No relationship was found between MSI and COPD severity. The most frequently affected marker was D14S588 (17.5% in COPD and 2.7% in asthma). The markers D6S344, G29802 and D13S71 showed alterations only in COPD, and G29802 was associated with a significantly decreased forced expiratory volume in one second FEV1 (% predicted), whereas MSI in D6S344 was associated with a significantly higher FEV1 (% pred). The frequency of microsatellite instability was higher in chronic obstructive pulmonary disease than in asthma, and microsatellite instability in three workers showed chronic obstructive pulmonary disease specificity. However, further studies are needed to verify the differences between chronic obstructive pulmonary disease and asthma at the microsatellite level.
Asunto(s)
Asma/diagnóstico , Inestabilidad de Microsatélites , Repeticiones de Microsatélite , Enfermedad Pulmonar Obstructiva Crónica/diagnóstico , Adulto , Anciano , Asma/genética , Biomarcadores/análisis , ADN/análisis , Diagnóstico Diferencial , Femenino , Marcadores Genéticos , Humanos , Masculino , Persona de Mediana Edad , Enfermedad Pulmonar Obstructiva Crónica/genética , Esputo/químicaRESUMEN
Peptidomimitism is applied to the medicinal chemistry in order to synthesize drugs that devoid of the disadvantages of peptides. AT1 antagonists constitute a new generation of drugs for the treatment of hypertension designed and synthesized to mimic the C-terminal segment of Angiotensin II and to block its binding action on AT1 receptor. An effort was made to understand the molecular basis of hypertension by studying the conformational analysis of Ang II and its derivatives as well as the AT1 antagonists belonging to SARTANs class of molecules. Such studies offer the possibility to reveal the stereoelectronic factors responsible for bioactivity of AT1 antagonists and to design and synthesize new analogs. An example will be given which proves that drugs with better pharmacological and financial profiles may arise based on this rational design.
Asunto(s)
Bloqueadores del Receptor Tipo 1 de Angiotensina II , Angiotensina II/análogos & derivados , Antihipertensivos/química , Diseño de Fármacos , 1-Sarcosina-8-Isoleucina Angiotensina II/análogos & derivados , 1-Sarcosina-8-Isoleucina Angiotensina II/química , Angiotensina II/química , Angiotensina II/farmacología , Antihipertensivos/síntesis química , Antihipertensivos/farmacología , Humanos , Hipertensión/tratamiento farmacológico , Losartán/análogos & derivados , Losartán/química , Espectroscopía de Resonancia Magnética , Conformación Molecular , Imitación Molecular , Péptidos/química , Péptidos/farmacología , Relación Estructura-ActividadRESUMEN
Biological membranes play an essential role in the drug action. They constitute the first barrier for drugs to exert their biological action. AT1 antagonists are amphiphilic molecules and are hypothesized to act on AT1 receptor through incorporation (first step) and lateral diffusion through membrane bilayers (second step). Various biophysical methods along with Molecular Modelling were applied in order to explore the plausible two step proposed mechanism of action for this class of antihypertensive drugs.
Asunto(s)
Bloqueadores del Receptor Tipo 1 de Angiotensina II , Antihipertensivos/química , Antihipertensivos/farmacología , Membrana Celular/efectos de los fármacos , Aminoácidos/química , Aminoácidos/metabolismo , Antihipertensivos/uso terapéutico , Sitios de Unión , Compuestos de Bifenilo/química , Compuestos de Bifenilo/farmacología , Rastreo Diferencial de Calorimetría , Membrana Celular/química , Membrana Celular/metabolismo , Humanos , Hipertensión/tratamiento farmacológico , Hipertensión/etiología , Imidazoles/química , Imidazoles/farmacología , Irbesartán , Losartán/química , Losartán/farmacología , Espectroscopía de Resonancia Magnética , Modelos Moleculares , Receptor de Angiotensina Tipo 1/química , Tetrazoles/química , Tetrazoles/farmacología , Difracción de Rayos XRESUMEN
Genetic alterations, such as loss of heterozygosity (LOH) or microsatellite instability (MI), have been reported in both malignant and benign disorders. In order to identify loci of deoxyribonucleic acid (DNA) mutation in asthma, MI and LOH were studied in sputum cells. DNA was extracted from cells in the sputum and blood cells of 22 patients with moderate asthma. Cells were analysed for MI and LOH using 18 polymorphic markers on chromosome 5q, 6p, 11q, 14q. Microsatellite analysis was also performed in six healthy subjects. None of the healthy individuals exhibited any genetic alteration. Genetic alterations were found in 16 of 22 asthmatic patients (73%). In total, 12 (54.5%) patients exhibited LOH only, one (4.5%) MI only, while three showed both MI and LOH. The highest incidence of LOH and MI was found on chromosome 14q. Mean immunoglobulin E and blood eosinophil levels were significantly higher in asthmatics with three or more genetic alterations. A high incidence of genetic alterations in the deoxyribonucleic acid of the sputum cells was found in asthmatic patients. Further studies are needed to identify the role of loss of heterozygosity and microsatellite instability in the investigation of genetic susceptibility of asthma and thus, in its pathogenesis.
Asunto(s)
Asma/genética , Inestabilidad Cromosómica/genética , Pérdida de Heterocigocidad/genética , Repeticiones de Microsatélite/genética , Adulto , Células Sanguíneas/química , Femenino , Predisposición Genética a la Enfermedad , Pruebas Genéticas/métodos , Humanos , Masculino , Persona de Mediana Edad , Esputo/química , Esputo/citologíaRESUMEN
Physicochemical methods were used to study the thermal and dynamic changes caused by losartan in the membrane bilayers. In addition, molecular modeling was implemented to explore its topography both in membranes and AT(1) receptor. Its incorporation resulted in the modification of thermal profile of dipalmitoyl phosphatidylcholine (DPPC) bilayers in a concentration dependent way up to 20mol% as it is depicted from the combination of differential scanning calorimetry (DSC) and MAS data. In particular, the presence of losartan caused lowering of the phase transition temperature and abolishment of the pretransition. T(1) experiments revealed the location of the drug into the membrane bilayers. The use of a combination of biophysical methods along with docking experiments brought out a possible two-step mechanism which involves incorporation of losartan at the interface of membrane bilayers and diffusion in the upper parts of AT(1) receptor helices IV-VII.
Asunto(s)
Membrana Celular/química , Losartán/química , Receptor de Angiotensina Tipo 1/química , Receptor de Angiotensina Tipo 1/metabolismo , Rastreo Diferencial de Calorimetría , Interacciones Hidrofóbicas e Hidrofílicas , Espectroscopía de Resonancia Magnética , Lípidos de la Membrana/química , Modelos Moleculares , Estructura Molecular , Conformación Proteica , Relación Estructura-Actividad , TemperaturaRESUMEN
Losartan is the first recently approved drug against hypertension disease that competes with the biological action of angiotensin II (AII) at the AT1 receptor. Its design was based on the mimicry of the C-terminal segment of AII. Due to the biological significance of Losartan, its structure elucidation and conformational properties are reported as determined by NMR spectroscopy and computational analysis. In addition, molecular modeling of the peptide Sarmesin [Sar1Tyr(OMe)4AII], a competitive antagonist of AII, was also developed based on NMR and computational analysis data. Sarmesin's C-terminal was used as a template for superimposition with specific molecular features of interest in the structure of Losartan such as the conformation of biphenyltetrazole, the n-butyl chain, and the orientation of hydroxymethylimidazole relative to the biphenyl template. The major conclusions derived from this study are the following: (a) Sarmesin, like the AII superagonist [Sar1]AII, adopts a conformation which keeps in close proximity the key amino acids Sar1 (or Arg2)-Tyr(OMe)4-His6-Phe8. (b) Losartan favors a low-energy conformation in which imidazole and tetrazole rings are placed in the opposite site relative to the spacer phenyl ring plane; the hydroxymethyl group is placed away from the spacer phenyl ring, the alkyl chain is oriented above the spacer phenyl ring, and the two phenyl rings deviate approximately 60 degrees from being coplanar. (c) Overlay of the C-terminal region of Sarmesin with Losartan using equivalent groups revealed an excellent match. (d) Interestingly, the matching between enantiomeric structures of Losartan was not equivalent, proposing that the chirality of this molecule is significant in order to exert its biological activity. These findings open a new avenue for synthetic chemists to design and synthesize peptidomimetic drugs based on the C-terminal segment of the proposed model of Sarmesin. The new candidate drug molecules are not restricted to structurally resemble Losartan as the design is hitherto focused.
Asunto(s)
Angiotensina II/análogos & derivados , Antihipertensivos/química , Hipertensión/etiología , Losartán/química , Angiotensina II/antagonistas & inhibidores , Angiotensina II/química , Antagonistas de Receptores de Angiotensina , Espectroscopía de Resonancia Magnética , Modelos Moleculares , Conformación Molecular , Método de Montecarlo , Conformación ProteicaRESUMEN
The synthetic cannabinoid (-)-2-(6a,7,10,10a-tetrahydro-6,6,9-trimethyl-1-hydroxy-6H-dibenzo[b,d]+ ++pyranyl)-2-hexyl-1,3-dithiolane (AMG-3) is a cannabimimetic molecular probe with one of the highest binding affinities reported to date. Therefore, due to its potential pharmacological importance, its structure was sought to be elucidated and its conformational properties were studied using a combination of 1D, 2D NMR spectroscopy and molecular modelling. The structure of its methylated analog (-)-2-(6a,7,10,10a-tetrahydro-6,6,9-trimethyl-6H dibenzo [b,d]pyranyl-1-methoxy)-2-hexyl-1,3 dithiolane (AMG-18), was also studied and its conformational properties were compared with AMG-3. AMG-18 lacks of the phenolic hydroxyl group a strict requirement for cannabimimetic activity and is almost devoid of any biological activity. The conformational analysis studies showed that 1',1' dithiolane ring restricted the orientation preferences of alkyl chain. This may account for the high binding affinity of AMG-3 to cananbinoid receptors. Grid scan search studies showed different preferences of possible adopting dihedral values of phenolic hydroxyl group and its methyl ether. These observations may account for their differences in biological activity.