Design of copper DNA intercalators with leishmanicidal activity

The complexes [Cu(dppz)(NO(3))]NO(3) (1), [Cu(dppz)(2)(NO(3))]NO(3) (2), [Cu(dpq)(NO(3))]NO(3) (3), and [Cu(dpq)(2)(NO(3))]NO(3) (4) were synthesized and characterized by elemental analysis, FAB-mass spectrometry, EPR, UV, and IR spectroscopies, and molar conductivity. DNA interaction studies showed that intercalation is an important way of interacting with DNA for these complexes. The biological activity of these copper complexes was evaluated on Leishmania braziliensis promastigotes, and the results showed leishmanicidal activity. Preliminary ultrastructural studies with the most active complex (2) at 1 h revealed parasite swelling and binucleated cells. This finding suggests that the leishmanicidal activity of the copper complexes could be associated with their interaction with the parasitic DNA.

Genetic contribution of major histocompatibility complex class II region to type 1 autoimmune hepatitis susceptibility in Venezuela

AIMS

Autoimmune hepatitis (AIH) is a progressive liver disease characterized by the presence of circulating autoantibodies, hypergammaglobulinaemia and a favourable response to immunosuppressive treatment. Although the pathogenesis of type 1 AIH is unknown, disease susceptibility is partially determined by genes linked to the class II region of the major histocompatibility complex. Type 1 AIH has been associated with DRB1*03, DRB1*04 and DRB3 alleles in European and North American Caucasians, with DRB1*0405 in Japanese, with DRB1*0404 in Mexican, and with DRB1*1301 in Argentinean populations.

METHODS

To analyse the molecular basis of these associations in Venezuela (mestizo population), we examined the frequency of human leucocyte antigens (HLA)-A -B -C, HLA-DQ and HLA-DR genes by low- and high-resolution oligonucleotide typing in a population of 41 type 1 AIH patients and 111 ethnic- and aged-matched healthy subjects.

RESULTS

The frequencies of both DRB1(*)1301 (P<0.0001) and DRB1*0301 (P<0.005) were significantly higher in patients than in controls. In addition, patients showed a strong association with the DRB3 allele (P<0.01). In contrast, the DQB1*04 allele was significantly decreased in the patient group (P<0.01). The frequencies of haplotypes A*01-B*08-DQB1*02-DRB1*03-DRB3, DQB1*05-DRB1*1301, DQB1*06-DRB1*1301 and A*02-DRB1*1301, B*45-DRB3 were significantly increased in type 1 AIH patients compared with the controls (P<0.01).

CONCLUSIONS

In conclusion, our data indicate that type 1 AIH predisposition in a Venezuelan mestizo population of different ethnic backgrounds is associated with DRB1*1301 and DRB1*0301 alleles. In addition, our findings suggest that protection against disease might be conferred by the DQB1*04 allele, with distinct ethnic differences from other populations.

HLA-DRB1*0402 haplotypes without DQB1*0302 in Venezuelan patients with pemphigus vulgaris

The two basic forms of autoimmune intraepidermal blistering diseases, pemphigus vulgaris (PV) and pemphigus foliaceus (PF), affect different layers of the skin, have different symptoms and target different antigens. We have defined human leukocyte antigen (HLA)-DRB1-DQB1 alleles and haplotypes in a case-control study of 66 non-Jewish patients attending a public reference Hospital over the past 10 years. The control group consisted of 101 matched individuals tested also by medium to high-resolution polymerase chain reaction-sequence-specific oligonucleotide with primers and probes from the 12th and 13th International Histocompatibility Workshop. Patients and controls were descendants of three-generation individuals born in the country. Among the patients, 49 had PV, 50% showed predominantly mucosal involvement, 50% showed predominantly the cutaneous clinical phenotype and 17 had PF. Statistically significant HLA-DR frequency differences between patients with PV and controls were found only for DRB1*0402 and DRB1*1401 [odds ratio (OR) = 27.22, confidence interval (CI) 94.7-7.82, P= 1.1 x 10(-14) and OR = 46.56, CI 801.4-2.70 P= 7.5 x 10(-6), respectively]. Both alleles were also increased in the patients with PF compared with the controls (OR = 7.0, P= 0.038 and OR = 21.64, P= 0.009, respectively), but the significance of the difference did not resist Bonferroni correction. Haplotype analysis showed that DRB1*0402 was always present with DQB1*0302 and DRB1*1401 with DQB1*0503, but no independent effect of the DQB1*0302 in the former haplotype was evident. Our results support the hypothesis that the DRB1*0402 without DQB1*0302 is the most relevant HLA-DRB1 allele responsible for the pathogenesis of pemphigus in Venezuelan patients with PV and discard the DQB1*0302 influence observed in other populations.

Role of genes GSTM1, GSTT1, and MnSOD in the development of late-onset Alzheimer disease and their relationship with APOE*4

INTRODUCTION

Several studies have reported increased oxidation of lipids, proteins and DNA in the brains of patients with Alzheimer disease (AD). Moreover, these patients display differences in the activity and polymorphisms of the genes encoding the enzymes GST (T1, M1) and MnSOD. For these reasons, we designed a study of the variability in GSTT1, GSTM1, and MnSOD genes in healthy and AD groups from a Venezuelan population.

METHODS

We included 179 unrelated Venezuelan subjects classified as either AD patients (n=79) or healthy individuals (n=100). Presence or absence of the GSTT1/GSTM1 genes was determined using PCR-SSP, and polymorphisms of MnSOD and APOE genes were identified with PCR-RFLP.

RESULTS

The genotype GSTT1+/GSTM1- seems to favour development of AD (OR=2.06, P=.01). The risk level is higher when it is combined with the ɛ4 allele of the APOE gene: GSTT1+/GSTM1-/ɛ3ɛ4 (OR=3.07, P=.05), GSTT1+/GSTM1-/ɛ4ɛ4 (OR=5.52, P=.02). The Ala-9Val polymorphism does not appear to be related to AD. However, the presence of the Ala/Ala genotype increases the risk provided by the ɛ4 allele of the APOE gene: AlaAla/ɛ3ɛ4 (OR=3.47, P=.03), AlaAla/ɛ4ɛ4 (OR=6.3, P=.01).

CONCLUSIONS

The results support the hypothesis that impaired mitochondrial function and increased oxidative damage are involved in the pathogenesis of AD. It is important to study other genes related to oxidative stress and antioxidant pathways which could be involved in susceptibility to AD.

Distribution of killer cell immunoglobulin-like receptor genes in the mestizo population from Venezuela

This study represents the first report on the distribution of KIR genes in 205 unrelated healthy mestizo Venezuelan individuals. Genotyping analysis showed that all KIR genes are present in this population. Frequency of inhibitory killer cell immunoglobulin-like receptors (KIRs) exceeded 0.69, except for KIR2DL2 (0.29) and 2DL5 (0.37). Activating KIRs showed low frequencies (0.11-0.29), except for KIR2DS4 (0.68). Forty-five different KIR genotypes were identified, with a predominance of three genotypes found in 50.7% of the population of which 25.9% were individuals homozygous for haplotype A. The frequencies of KIR genes reflect the ethnic admixture existing in the mestizo Venezuelan population.

Human leukocyte antigen class I and MICA haplotypes in a multicase family with Cladophialophora carrionii chromoblastomycosis

Previous studies carried out in an endemic semiarid region northwest of Venezuela at Falcon State have shown a prevalence of 15.4/1000 of chromoblastomycosis following traumatisms with xenophile vegetation infected with Cladophialophora carrionii. We performed high-resolution DNA typing of human leukocyte antigen (HLA)-A, -B and -C and major histocompatibility complex class I chain related gene A (MICA) alleles and segregation analysis in 49 members of one extended family with 12 affected individuals, who have lived for approximately 70 years in this endemic zone. None of the alleles, haplotypes or genotypes is shared by all the patients. No deviation from the expected HLA haplotype distribution or association of chromoblastomycosis with HLA-A, -B and -C haplotypes was observed. Further, a haplotype-sharing transmission/disequilibria testing of 11 nuclear families did not give enough evidence to claim linkage (P = 0.398), suggesting that genes located in the short arm of chromosome 6 may not be relevant in the immune response toward infection with C. carrionii in this Venezuelan endemic zone. Deleted MICA alleles on HLA-B*4802 haplotypes were present among several members of the extended family, but only two of them were affected.

[Study of the association between the polymorphism of the TNF-α gene and prostate cáncer]

BACKGROUND

Prostate cancer is the third cause of cancer death in men in the Western hemisphere and the second cause of cancer death in Zulian men from Venezuela.

OBJECTIVE

To determine whether polymorphisms 308 and 238 of the tumor necrosis factor alpha (TNF-α) gene are associated with prostate cancer.

METHODS

The DNA that was extracted from the peripheral blood of 40 patients with prostatic specific antigen and 40 controls was amplified by PCR plus digestion with enzymes NcoI and MspI.

RESULTS

In the patients, genotypes of the TNF-α-238 polymorphism were observed in 90% GG and 10% GA; in controls, in 97.5% GG and 2.5% GA, odds ratio (OR) = 4,000 for GA. In the patients, genotypes of TNF-α-308 polymorphism were identified in 85% GG and 15% GA, and in controls in 72.5% GG and 27.5% GA, OR = 0.545 for GA and 1.172 for GG. The allelic frequencies for TNF-α-238 in patients were 95% for G and 5% for A; in controls, 98.75% for G and 1.25% for A, with OR = 4,000 for A. The allelic frequencies for TNF-α-308 in the patients were 92.5% for G and 7.5% for A.

CONCLUSIONS

There weren't any statistically significant associations. The allele A of the TNF-α-238 polymorphism resulted in a considerable risk factor for prostate cancer.

Postprandial Hypertriglyceridemia Is Associated with the Variant 54 Threonine FABP2 Gene

Purpose: Fasting or postprandial hypertriglyceridemia is considered an independent cardiovascular disease (CVD) risk factor. The intestinal fatty acid binding protein (FABP2) is involved in the intracellular transport and metabolism of fatty acids. The presence of the Ala54Thr polymorphism of the FABP2 gene appears to be involved in postprandial hypertriglyceridemia. We explored the possible association of the Ala54Thr polymorphism with fat intolerance in apparently healthy, fasting, normolipidemic subjects with normal body-mass index and without diabetes. Methodology: A total of 158 apparently healthy individuals were classified as fat tolerant (n = 123) or intolerant (n = 35) according to their response (plasma triglycerides) to an oral abbreviated tolerance test with blood samples taken at 0, 2 and 4 h. At 0 h, all subjects ingested 26.3 g of fats. Presence of the Ala54Thr polymorphism of the FABP2 gene was evaluated by polymerase chain reaction⁻restriction fragment length (PCR⁻RFLP). Results: The group with fat intolerance (postprandial hypertriglyceridemia group) showed an increased frequency of the Thr54Thr genotype when compared with the group with normal fat tolerance (control group) (23% vs. 4%, respectively, OR: 16.53, 95% CI: 4.09⁻66.82, p: 0.0001, pc: 0.0003). Carriers of at least one Thr54 allele were up to six times more prevalent in the fat intolerant group than in the non-carriers. (OR: 6.35; 95% CI: 1.86⁻21.59, p: 0.0003, pc: 0.0009). The levels of plasma triglycerides (Tg) at 4 h after the test meal were higher in carriers of at least one 54Thr allele than in carriers of the Ala54 allele (p < 0.05). Conclusions: There is a significant association between postprandial hypertriglyceridemia and the presence of at least one 54Thr allele of the FABP2 gene. In addition, subjects with this genotype showed an increased ratio of Tg/HDL-cholesterol. This parameter is a marker of increased CVD risk and insulin resistance.

Polimorfismo de genes de citocinas: ¿factores de riesgo cardiovascular en la población venezolana?

Objective

To examine whether the polymorphisms of the IL6, TNFA and IL10 genes represent a risk marker for acute myocardial infarction (AMI) and to analyze their correlation with risk factors, age of occurrence and type of AMI.

Method

Association study that included 310 unrelated Venezuelan individuals, grouped in 190 patients with AMI and 120 controls with or without cardiovascular risk factors. The IL6-174 G/C (rs1800795), TNFA -308 G/A (rs1800629), and IL10-1082 A/G (rs1800896), -819 C/T (rs1800871) and -592 C/A (rs1800872) polymorphisms were determined using the polymerase chain reaction technique with sequence-specific primers.

Results

Comparison of genotypic and allelic frequencies, using adjusted logistic regression analysis for risk factors, showed a significantly increased frequency of the genotype combination G/G-A/A of TNFA-308 G/A (odds ratio [OR]: 3.8; p = 0.00007), GG/-C/C of IL6-174 G/C (OR: 2.3; p = 0.009), A/G-G/G of IL10-1082 A/G (OR: 3.8; p = 0.00001) and the GCC haplotype of IL10 (OR: 3.71; p = 0.0053) in infarcted patients compared to controls. Interactions between the IL10-1082 A/G and TNFA-308 G/A polymorphisms and hypertension were observed.

Conclusions

The association of the variants of the TNFA, IL6 and IL10 genes with AMI suggest that the imbalance in the production of cytokines promotes an exacerbated inflammatory process, supporting the fundamental role of inflammation in all stages of the atherosclerotic process.

Genetic Polymorphisms at Four STR Loci from the HLA Region in a Venezuelan Population

POPULATIONS

Whole blood samples from 74 unrelated healthy individuals were collected. The donors' sample included Venezuelan mestizos from various regions of the country, but mostly from the resident population of Caracas City. A Venezuelan mestizo is the offspring of a mating between a native Venezuelan and a person born in Europe, mainly in Spain.

Factores genéticos del hospedero involucrados en la susceptibilidad y gravedad de la COVID-19

Introducción: La infección por SARS-CoV-2 determina desde formas asintomáticas hasta manifestaciones muy graves de COVID-19 que pueden comprometer la vida. El impacto de la pandemia por COVID-19 plantea la necesidad de identificar los factores de riesgo que condicionan la variabilidad interindividual en la susceptibilidad a la infección por SARS-CoV-2, la fisiopatología y la progresión de la enfermedad. Varios autores sugieren que el componente genético juega un papel clave en la compleja interacción existente virus-hospedero, donde las diferencias poblacionales dirigen tal heterogeneidad. Métodos: Se realizó una revisión bibliográfica de la literatura científica, publicada hasta los momentos, relacionada con los marcadores biológicos que participan en la evolución de la infección por SARS-CoV-2 y los polimorfismos de moléculas potencialmente involucradas en la compleja interacción virus-hospedero. Hallazgos de interpretación: Numerosas evidencias señalan que variantes alélicas de genes que codifican para moléculas que actúan en las etapas tempranas de interacción del virus con la célula o en eventos que determinan la respuesta inmunitaria del hospedero, podrían favorecer la infección por SARS-CoV-2 o la gravedad de la enfermedad. El grupo sanguíneo ABO pareciera jugar un papel en la inmunopatogénesis, mostrando los individuos de grupo O un menor riesgo a infectarse con SARS-CoV-2, aunque otros componentes del hospedero, genéticos, fisiológicos y metabólicos, como la expresión diferencial de receptores tipo toll, antígenos HLA, citocinas proinflamatorias, quimiocinas u otros efectores de la respuesta inmunitaria innata y dquirida, estarían también participando. Reflexiones finales: El éxito y progresión de la infección viral hacia el desarrollo de una manifestación clínica y su gravedad dependen, en gran medida, de la interacción entre factores virales y la respuesta del hospedero, que a su vez está condicionada por factores genéticos, epigenéticos y comorbilidades preexistentes. La contribución del componente genético plantea la potencial aplicación de estrategias preventivas dirigidas, la identificación de blancos terapéuticos y el desarrollo de nuevos fármacos.