The usefulness of the genetic panel in the classification and refinement of diagnostic accuracy of Mexican patients with Marfan syndrome and other connective tissue disorders

Marfan syndrome (MFS) is a multisystem genetic disorder with over 3000 mutations described in the fibrillin 1 (FBN1) gene. Like MFS, other connective tissue disorders also require a deeper understanding of the phenotype-genotype relationship due to the complexity of the clinical presentation, where diagnostic criteria often overlap. Our objective was to identify mutations in patients with connective tissue disorders using a genetic multipanel and to analyze the genotype-phenotype associations in a cohort of Mexican patients. We recruited 136 patients with MFS and related syndromes from the National Institute of Cardiology. Mutations were identified using next-generation sequencing (NGS). To examine the correlation between mutation severity and severe cardiovascular conditions, we focused on patients who had undergone Bentall-de Bono surgery or aortic valve repair. The genetic data obtained allowed us to reclassify the initial clinical diagnosis across various types of connective tissue disorders. The transforming growth factor beta receptor 2 (TGFBR2) rs79375991 mutation was found in 10 out of 16 (63%) Loeys-Dietz patients. We observed a high prevalence (65%) of more severe mutations, such as frameshift indels and stop codons, among patients requiring invasive treatments like aortic valve-sparing surgery, Bentall and de Bono procedures, or aortic valve replacement due to severe cardiovascular injury. Although our study did not achieve precise phenotype-genotype correlations, it underscores the importance of a multigenetic panel evaluation. This could pave the way for a more comprehensive diagnostic approach and inform medical and surgical treatment decision-making.

Evaluation of the participation of ABCA1 transporter in epicardial and mediastinal adipose tissue from patients with coronary artery disease

Objective

Recent studies have shown a relationship between adipose tissue and coronary artery disease (CAD). The ABCA1 transporter regulates cellular cholesterol content and reverses cholesterol transport. The aim of this study was to determine the relationship between single nucleotide polymorphisms (SNPs) R230C, C-17G, and C-69T and their expression in epicardial and mediastinal adipose tissue in Mexican patients with CAD.

Subjects and methods

The study included 71 patients with CAD and a control group consisting of 64 patients who underwent heart valve replacement. SNPs were determined using TaqMan probes. mRNA was extracted using TriPure Isolation from epicardial and mediastinal adipose tissue. Quantification and expression analyses were done using RT-qPCR.

Results

R230C showed a higher frequency of the GG genotype in the CAD group (70.4%) than the control group (57.8%) [OR 0.34, 95% CI (0.14-0.82) p = 0.014]. Similarly, C-17G (rs2740483) showed a statistically significant difference in the CC genotype in the CAD group (63.3%) in comparison to the controls (28.1%) [OR 4.42, 95% CI (2.13-9.16), p = 0.001]. mRNA expression in SNP R230C showed statistically significant overexpression in the AA genotype compared to the GG genotype in CAD patients [11.01 (4.31-15.24) vs. 3.86 (2.47-12.50), p = 0.015].

Conclusion

The results suggest that the GG genotype of R230C and CC genotype of C-17G are strongly associated with the development of CAD in Mexican patients. In addition, under-expression of mRNA in the GG genotype in R230C is associated with patients undergoing revascularization.

Analysis of GPR126 polymorphisms and their relationship with scoliosis in Marfan syndrome and Marfan-like syndrome in Mexican patients

Marfan syndrome (MFS) is an inherited connective tissue disorder. As the spinal growth depends on delicate balance of forces, conditions that affect musculoskeletal matrix often lead to spinal deformities. A large cross-sectional study revealed a 63% prevalence of scoliosis among patients with MFS. Multi-ethnic genome-wide association studies and analyses of human genetic mutations showed that variations and mutations of G protein-coupled receptor 126 (GPR126)locus are associated with multiple skeletal defects, including shorter stature and adolescent idiopathic scoliosis. The study included 54 patients with MFS and 196 control patients. The DNA was extracted from peripheral blood using the saline expulsion method and single nucleotide polymorphism (SNP) determination was carried out using TaqMan probes. Allelic discrimination was performed by RT-qPCR. Significant differences in genotype frequencies were found for SNP rs6570507 in relation to MFS and sex (recessive model, OR 2.46, 95% CI 1.03 -5.87; P = 0.03) and rs7755109 (overdominant model, OR 0.39, 95% CI 0.16-0.91; P = 0.03). The most significant association was found in SNP rs7755109, where the frequency of genotype AG was significantly different between MFS patients with scoliosis and those without (OR 5.68, 95% CI 1.09-29.48; P=0.04). This study, for the first time, examined the genetic association of SNP GPR126 with the risk of scoliosis in patients with connective tissue diseases. The study revealed that SNP rs7755109 is associated with the presence of scoliosis in Mexican patients with MFS.

Overexpression of microRNA-21-5p and microRNA-221-5p in Monocytes Increases the Risk of Developing Coronary Artery Disease

MicroRNAs (miRs) regulate gene expression at the post-transcriptional level and are found to be present in monocytes. This study aimed to investigate miR-221-5p, miR-21-5p, and miR-155-5p, their expression in monocytes, and their role in coronary arterial disease (CAD). The study population comprised 110 subjects, and RT-qPCR was used to examine the miR-221-5p, miR-21-5p, and miR-155-5p expressions in monocytes. Results: the miR-21-5p (p = 0.001) and miR-221-5p (p < 0.001) expression levels were significantly higher in the CAD group, and the miR-155-5p (p = 0.021) expression levels were significantly lower in the CAD group; only miR-21-5p and miR-221-5p upregulation was found to be associated with an increased CAD risk. The results show significant increases in miR-21-5p in the unmedicated CAD group with the metformin patients vs. the healthy control group (p = 0.001) and vs. the medicated CAD group with metformin (p = 0.022). The same was true for miR-221-5p in the CAD patients unmedicated with metformin vs. the healthy control group (p < 0.001). Our results from Mexican CAD patients show that the overexpression in monocytes of miR-21-5p and miR-221-5p increases the risk of the development of CAD. In addition, in the CAD group, the metformin downregulated the expression of miR-21-5p and miR-221-5p. Also, the expression of endothelial nitric oxide synthase (NOS3) decreased significantly in our patients with CAD, regardless of whether they were medicated. Therefore, our findings allow for the proposal of new therapeutic strategies for the diagnosis and prognosis of CAD and the evaluation of treatment efficacy.

Expressions of mRNA and encoded proteins of mitochondrial uncoupling protein genes (UCP1, UCP2, and UCP3) in epicardial and mediastinal adipose tissue and associations with coronary artery disease

Objective

To evaluate the expression of UCP1, UCP2, and UCP3 mRNA and encoded proteins in epicardial and mediastinal adipose tissues in patients with coronary artery disease (CAD).

Subjects and methods

We studied 60 patients with CAD and 106 patients undergoing valve replacement surgery (controls). Expression levels of UCP1, UCP2, and UCP3 mRNA and encoded proteins were measured by quantitative real-time PCR and Western blot analysis, respectively.

Results

: We found increased UCP1, UCP2, and UCP3 mRNA levels in the epicardial adipose tissue in the CAD versus the control group, and higher UCP1 and UCP3 mRNA expression in the epicardial compared with the mediastinal tissue in the CAD group. There was also increased expression of UCP1 protein in the epicardial tissue and UCP2 protein in the mediastinum tissue in patients with CAD. Finally, UCP1 expression was associated with levels of fasting plasma glucose, and UCP3 expression was associated with levels of high-density lipoprotein cholesterol and low-density cholesterol in the epicardial tissue.

Conclusion

Our study supports the hypothesis that higher mRNA expression by UCP genes in the epicardial adipose tissue could be a protective mechanism against the production of reactive oxygen species and may guard the myocardium against damage. Thus, UCP levels are essential to maintain the adaptive phase of cardiac injury in the presence of metabolic disorders.

Impact on the Clinical Evolution of Patients with COVID-19 Pneumonia and the Participation of the NFE2L2/KEAP1 Polymorphisms in Regulating SARS-CoV-2 Infection

In patients with severe pneumonia due to COVID-19, the deregulation of oxidative stress is present. Nuclear erythroid factor 2 (NRF2) is regulated by KEAP1, and NRF2 regulates the expression of genes such as NFE2L2-KEAP1, which are involved in cellular defense against oxidative stress. In this study, we analyzed the participation of the polymorphisms of NFE2L2 and KEAP1 genes in the mechanisms of damage in lung disease patients with SARS-CoV-2 infection. Patients with COVID-19 and a control group were included. Organ dysfunction was evaluated using SOFA. SARS-CoV-2 infection was confirmed and classified as moderate or severe by ventilatory status and by the Berlin criteria for acute respiratory distress syndrome. SNPs in the gene locus for NFE2L2, rs2364723C>G, and KEAP1, rs9676881A>G, and rs34197572C>T were determined by qPCR. We analyzed 110 individuals with SARS-CoV-2 infection: 51 with severe evolution and 59 with moderate evolution. We also analyzed 111 controls. Significant differences were found for rs2364723 allele G in severe cases vs. controls (p = 0.02); for the rs9676881 allele G in moderate cases vs. controls (p = 0.04); for the rs34197572 allele T in severe cases vs. controls (p = 0.001); and in severe vs. moderate cases (p = 0.004). Our results showed that NFE2L2 rs2364723C>G allele G had a protective effect against severe COVID-19, while KEAP1 rs9676881A>G allele G and rs34197572C>T minor allele T were associated with more aggressive stages of COVID-19.

Polymorphisms in TNFAIP3, but not in STAT4, BANK1, BLK, and TNFSF4, are associated with susceptibility to Takayasu arteritis

BACKGROUND

Takayasu arteritis (TAK) is considered a rare disease characterized by nonspecific inflammation of the large arteries, especially the aorta and its major branches. Because TAK is an autoimmune disease (AD), it could share susceptibility loci with other pathologies such as systemic lupus erythematosus (SLE), and rheumatoid arthritis (RA), among others. Widely explored polymorphisms in non-HLA genes, including TNFAIP3, STAT4, TNFSF4, BANK1, and BLK have been consistently associated with both SLE and RA, but they have not been evaluated in TAK.

OBJECTIVE

The aim of our study was to investigate whether TNFAIP3, STAT4, BANK1, BLK, and TNFSF4 polymorphisms are associated with susceptibility to TAK.

METHODS

The TNFAIP3 rs2230926T/G and rs5029924C/T, STAT4 rs7574865G/T, BANK1 10516487G/A, BLK rs2736340T/C, rs13277113A/G, and TNFS4 rs2205960G/T polymorphisms were genotyped in 101 cases and 276 controls by using a TaqMan SNP genotyping assay. An association analysis was performed.

RESULTS

The TNFAIP3 rs2230926T/G and rs5029924C/T polymorphisms were in complete linkage disequilibrium and turned out to be risk factors for TAK (OR = 4.88, p = 0.0001). The STAT4, BANK1, BLK, and TNFSF4 polymorphisms were not associated with the disease.

CONCLUSIONS

This is the first study documenting an association of TNFAIP3 rs2230926T/G and rs5029924C/T with TAK. Our results provide new information on the genetic bases of TAK.

Monocyte Low-Density Lipoprotein Receptor-Related Protein 1 (LRP1) Expression Correlates with cIMT in Mexican Hypertensive Patients

Fundamento

A hipertensão arterial (HTA) representa um grande fator de risco de morbidade e mortalidade cardiovascular. Ainda não se sabe que mecanismos moleculares específicos estão associados ao desenvolvimento de hipertensão essencial.

Objetivo

Neste trabalho, analisamos a associação entre expressão mRNA de monócito LRP1, expressão de proteína LRP1, e espessura íntima-média de carótida (EIMC) de pacientes com hipertensão essencial.

Métodos

A expressão mRNA de monócito LRP1 e os níveis de proteína e EIMC foram quantificados em 200 indivíduos mexicanos, sendo 91 normotensos (NT) e 109 hipertensos (HT) A significância estatística foi definida em p < 0,05.

Resultados

O grupo de pacientes HT tinha EIMC maior altamente significativa em comparação com os pacientes NT (p = 0,002), e isso está relacionado ao aumento na expressão mRNA de LRP1 (6,54 versus. 2,87) (p = 0,002) e expressão de proteína LRP1 (17,83 versus 6,25), respectivamente (p = 0,001). Essas diferenças foram mantidas mesmo quando dividimos nossos grupos de estudo, levando em consideração apenas aqueles que apresentavam dislipidemia na expressão de mRNA (p = 0,041) e de proteínas (p < 0,001). Também se identificou que a indução de LRP1 mediada por LRP1 em monócitos em de maneira dependente de dose e tempo, com diferença significativa em NT versus HT (0,195 ± 0,09 versus 0,226 ± 0,12, p = 0,046).

Conclusão

Foi encontrado um aumento em EIMC em indivíduos com hipertensão, associada a expressões de proteína LRP1 e mRNA mais altas em monócitos, independente da presença de dislipidemia em pacientes HT. Esses resultados que a upregulation de LRP1 em monócitos de pacientes hipertensos mexicanos poderia estar envolvida na diminuição da EIMC. (Arq Bras Cardiol. 2021; 116(1):56-65)

Association between the transporters ABCA1/G1 and the expression of miR-33a/144 and the carotid intima media thickness in patients with arterial hypertension

ATP-binding cassette membrane transporters (ABC), functions as an outflow facilitator of phospholipids and cellular cholesterol, playing an important role in the development of atherosclerosis and arterial hypertension. ABC's transporters could post-transcriptionally regulated by miRs. Evaluate the association in the transporters ABCA1 and ABCG1 with the expression of miR-33a and miR-144 and the carotid intima media thickness (cIMT) in patients with essential arterial hypertension. The miR-33a-5p, miR-144-3p and mRNA ABCA1 and ABCG1 expression in monocytes from Mexican hypertensive patients were examined by RT-PCR. The miR-33a and miR-144 expression in monocytes and mRNA ABCA1 and ABCG1 from Mexican hypertensive patients were examined by RT-PCR. This study involved 84 subjects (42 normotensive subjects and 42 patients with essential hypertension). Our study revealed that miR-33a expression (p = 0.001) and miR-144 (p = 0.985) were up-regulated, meanwhile, ABCA1 and ABCG1 transporters were down-regulated (p = 0.007 and p = 0.550 respectively) in hypertensive patients compared with the control group. The trend remains for miR33a/ABCA1 in presence of cIMT. Moreover, an inverse correlation was found with the expression levels of ABCA1 and ABCG1 as well as in HDL-C with miR-33a and miR-144. Our results showed an increase in the expression of miR-33a and miR-144 and an inverse correlation in their target ABCA1 and ABCG1; it may be associated with essential arterial hypertension in patients with cIMT and as consequence for atheromatous plaque.

Lack of Association between Cytokine Genetic Polymorphisms in Takayasu's Arteritis in Mexican Patients

Aim: To investigate the relation between polymorphisms in the interleukin 10 (IL)-10, tumor necrosis factor (TNF)-α, transforming growth factor (TGF)-β and interferon (IFN)-γ genes and Takayasu's arteritis in the Mexican population. Methods: A case-control study was performed to investigate the associations of IL-10, TNF-α, TGF-β and IFN-γ polymorphisms in a sample of 52 Takayasu's arteritis patients, diagnosed according to the criteria of the American College of Rheumatology and EULAR PRINTO criteria when the patients were under 18 years of age; 60 clinically healthy unrelated Mexican individuals by the 5' exonuclease TaqMan polymerase chain reaction. Polymorphic haplotypes were constructed after linkage disequilibrium analysis. Results: Significant differences were not found in the distribution for genotype and allele frequencies of the polymorphisms studied between healthy controls and Takayasu´s arteritis patients. Likewise, significant associations were not detected in the haplotype analysis with the different genes studied. Conclusions: These findings suggest that the polymorphisms in IL-10, TNF-α, TGF-β and IFN-γ might not contribute to the susceptibility of Takayasu´s arteritis in the Mexican population.

Para-occupational exposure to pesticides, PON1 polymorphisms and hypothyroxinemia during the first half of pregnancy in women living in a Mexican floricultural area

BACKGROUND

Adequate maternal thyroxine (T4) concentrations during the first half of pregnancy are fundamental to the embryo's or fetus' neural development. Organophosphate pesticides (OP) can act as thyroid disruptors and genetic polymorphisms for paraoxonase 1 (PON1), an enzyme that detoxifies OP, could be involved in individual's susceptibility to them. We assessed the association between para-occupational exposure to pesticides, including OP, during pregnancy and maternal hypothyroxinemia, as well as the potential genetic susceptibility conferred by PON1 polymorphisms.

METHODS

We analyzed information from 381 healthy pregnant women (< 17 gestational weeks), who lived in a floricultural region of Mexico where pesticides, including OP, are routinely used. Women who were para-occupationally exposed to pesticides were those whose partner had an occupation involving contact with these products. Thyroid-Stimulating Hormone (TSH) and free T4 concentrations were determined using ELISA, and hypothyroxinemia was defined as free T4 concentrations <0.76 ng/dL. PON1192QR, PON155LM and PON1-108CT polymorphisms were determined through Polymerase Chain Reaction (PCR). The association between para-occupational exposure and genetic polymorphisms and hypothyroxinemia was estimated using logistic regression models.

RESULTS

One hundred and sixty two women (42.52%) were classified as para-occupationally exposed to pesticides. Hypothyroxinemia prevalence was 54%, and it was not significantly associated with pesticide para-occupational exposure (OR: 1.21 95% CI 0.75-1.94). Independently of para-occupational exposure, the likelihood of hypothyroxinemia was higher among women who were carriers of PON155MM than in those with PON155LL genotype (OR _{MM vs LL}: 3.03; 95%CI 1.62, 5.70). PON1192 RR (OR _{RR vs QQ}: 1.72; 95%CI 0.93, 3.17) and PON1-108TT (OR _{TT vs CC}: 1.60; 95%CI 0.90, 2.70) genotypes were marginally associated with hypothyroxinemia. No significant interaction was observed between pesticides para-occupational exposure and PON1 polymorphisms.

CONCLUSIONS

These results suggest that PON1 polymorphisms could affect thyroid function during pregnancy in women living in areas where pesticides, including OP, are routinely used. Low exposure variability in this population, could be a possible explanation for the lack of association between para-occupational exposure and thyroid function.

Polymorphisms C677T and A1298C of MTHFR Gene: Homocysteine Levels and Prothrombotic Biomarkers in Coronary and Pulmonary Thromboembolic Disease

The activity of the enzyme methylenetetrahydrofolate reductase (MTHFR) determines homocysteine (Hcy) levels, and polymorphisms in its gene affect the activity of the enzyme. Changes in the enzyme’s activity may lead to a higher susceptibility to develop arterial and venous thromboembolic disease. The aim was to analyze the relationship between the C677T and A1298C polymorphisms of MTHFR, Hcy levels, and prothrombotic biomarkers in pulmonary embolism (PE) and acute myocardial ischemia (AMI). Clinical files of patients with thromboembolic diseases having complete data and whose doctor had requested an assay to determine the polymorphisms of the MTHFR gene, Hcy levels, and prothrombotic biomarkers were studied to search for the correlation between mutations of the MTHFR gene and Hcy levels in the different diseases. We included 334 files: 158 were from women and 176 from men (51 [19 SD] years). Sixty-three percent have had thrombosis, 8% AMI, and 31% PE. Patients with thrombosis had elevated frequency of the C677T polymorphism. The CC genotype was higher than the TT genotype (P = .003) and CT versus the TT (P = .009). In patients with PE, the CC genotype was higher than the TT genotype (P = .038). Pulmonary embolism with massive and submassive events had predominant genotypes 677 TT (P = .003) and the AA 1298 (P = .017). Elevated Hcy levels in the presence of the T allele in the C677T gene and of the A allele in the A1298C gene are associated with AMI and massive and submassive PE.

The UCP2 -866G/A, Ala55Val and UCP3 -55C/T polymorphisms are associated with premature coronary artery disease and cardiovascular risk factors in Mexican population

We examined the role of UCP gene polymorphisms as susceptibility markers for premature coronary artery disease (pCAD). The UCP2 Ala55Val (C/T rs660339), UCP2 -866G/A (rs659366), and UCP3 -55C/T (rs1800849) polymorphisms were genotyped in 948 patients with pCAD, and 763 controls. The distribution of the UCP2 A55V (C/T rs660339) and UCP3 -55 (rs1800849) was similar in patients and controls. However, under a recessive model, the UCP2 -866 (rs659366) A allele was associated with increased risk of developing pCAD (OR = 1.43, Pc = 0.003). On the other hand, patients with pCAD and UCP2 A55V (rs660339) TT showed high levels of visceral abdominal fat (VAF) (Pc = 0.002), low levels of subcutaneous abdominal fat (SAF) (Pc = 0.001) and high VAT/SAT ratio (Pc < 0.001). Also, patients with UCP2 -866 (rs659366) AA showed increased levels of VAF (Pc = 0.003), low levels of SAF (Pc = 0.001) and a high VAT/SAT ratio (Pc = 0.002), whereas patients with the UCP3 -55 (rs1800849) TT presented high levels of VAF (Pc = 0.002). The results suggest the association of the UCP2 -866 (rs659366) polymorphism with risk of developing pCAD. Some polymorphisms were associated with abdominal fat levels and cardiovascular risk factors.

Association between UCP polymorphisms and adipokines with obesity in Mexican adolescents

BACKGROUND

It has been reported that the uncoupling proteins (UCPs) can contribute to energy metabolism, and are thus involved in the pathogenesis of obesity. The objective of the study was to analyze the association between UCP polymorphisms, clinical parameters and leptin and adiponectin plasma levels in an adolescent population with overweight and obesity.

METHODS

We analyzed the UCP1 -3826 C/T, UCP2-866 G/A, Ala55Val and UCP3 -55 C/T polymorphisms and the levels of adipokines in adolescents with normal weight and with overweight or obesity. The study included 270 students aged between 12 and 18 years categorized according to the percentiles from Mexico City. Adipokines levels were measured by immunoassay methods and the UCP polymorphisms were determined using Taqman real-time polymerase chain reaction (RT-PCR).

RESULTS

No significant differences were found in the UCP polymorphisms in seven inheritance models studied. Most of the significant differences in the clinical parameters were found under a recessive model, the UCP2 -866 polymorphism was associated with diastolic blood pressure (p=0.008), triglycerides (p=0.045), low-density lipoprotein-cholesterol (LDL-C) (p=0.003), high-density lipoprotein-cholesterol (HDL-C) (p=0.050) and plasma levels of leptin (p<0.001). Also, the obese group was found to have higher leptin levels and lower adiponectin levels in GA+AA vs. GG (recessive model).

CONCLUSIONS

This study demonstrated a direct relationship between the clinical characteristics and UCP2-866 in a recessive model, associated with high levels of leptin and decreased levels of adiponectin in an obese or overweight Mexican adolescent population.

DHEA increases epithelial markers and decreases mesenchymal proteins in breast cancer cells and reduces xenograft growth

Breast cancer is one of the most common neoplasias and the leading cause of cancer death in women worldwide. Its high mortality rate is linked to a great metastatic capacity associated with the epithelial-mesenchymal transition (EMT). During this process, a decrease in epithelial proteins expression and an increase of mesenchymal proteins are observed. On the other hand, it has been shown that dehydroepiandrosterone (DHEA), the most abundant steroid in human plasma, inhibits migration of breast cancer cells; however, the underlying mechanisms have not been elucidated. In this study, the in vitro effect of DHEA on the expression pattern of some EMT-related proteins, such as E-cadherin (epithelial), N-cadherin, vimentin and Snail (mesenchymal) was measured by Western blot and immunofluorescence in MDA-MB-231 breast cancer cells with invasive, metastatic and mesenchymal phenotype. Also, the in vivo effect of DHEA on xenograft tumor growth in nude mice (nu^-/nu^-) and on expression of the same epithelial and mesenchymal proteins in generated tumors was evaluated. We found that DHEA increased expression of E-cadherin and decreased N-cadherin, vimentin and Snail expression both in MD-MB-231 cells and in the formed tumors, possibly by DHEA-induced reversion of mesenchymal phenotype. These results were correlated with a tumor size reduction in mouse xenografts following DHEA administration either a week earlier or concurrent with breast cancer cells inoculation. In conclusion, DHEA could be useful in the treatment of breast cancer with mesenchymal phenotype.

Glutathione system participation in thoracic aneurysms from patients with Marfan syndrome

BACKGROUND

Aortic dilatation in Marfan syndrome (MFS) is progressive. It is associated with oxidative stress and endothelial dysfunction that contribute to the early acute dissection of the vessel and can result in rupture of the aorta and sudden death. We evaluated the participation of the glutathione (GSH) system, which could be involved in the mechanisms that promote the formation and progression of the aortic aneurysms in MFS patients.

PATIENTS AND METHODS

Aortic aneurysm tissue was obtained during chest surgery from eight control subjects and 14 MFS patients. Spectrophotometrical determination of activity of glutathione peroxidase (GPx), glutathione-S-transferase (GST), glutathione reductase (GR), lipid peroxidation (LPO) index, carbonylation, total antioxidant capacity (TAC), and concentration of reduced and oxidized glutathione (GSH and GSSG respectively), was performed in the homogenate from aortic aneurysm tissue.

RESULTS

LPO index, carbonylation, TGF-β1, and GR activity were increased in MFS patients (p < 0.04), while TAC, GSH/GSSG ratio, GPx, and GST activity were significantly decreased (p < 0.04).

CONCLUSIONS

The depletion of GSH, in spite of the elevated activity of GR, not only diminished the activity of GSH-depend GST and GPx, but increased LPO, carbonylation and decreased TAC. These changes could promote the structural and functional alterations in the thoracic aorta of MFS patients.

Dehydroepiandrosterone inhibits events related with the metastatic process in breast tumor cell lines

Dehydroepiandrosterone (DHEA), an adrenal hormone, has a protective role against cancer. We previously shown that DHEA inhibits the proliferation and migration of cell lines derived from breast cancer; however, the role of DHEA in others events related with these effects are unknown. We hypothesized that DHEA inhibits the expression of proteins and some events related with cell migration and metastasis. We determined the migration in Boyden chambers, the invasion in matrigel, anchorage-independent growth and the formation of spheroids in 3 cell lines (MCF-7, MDA-MB-231, ZR-75-30) derived from breast cancer exposed to DHEA. The secretion of metalloproteinases (MMPs), tissue inhibitors of metalloproteinases (TIMPs), and several pro-inflammatory molecules in the secretome of these cells was also evaluated.  DHEA inhibited the migration in transwells and the invasion in matrigel of MCF-7 and MDA-MB-231 cells. Besides, DHEA inhibited the anchorage-independent growth on agar and decreased the size of spheroids, and also reduced the secretion of IL-1α, IL-6, IL-8, and TNF-α in all cell lines. Metalloproteinase-1 (MMP-1) secretion was slightly decreased by DHEA treatment in MDA-MB-231 cells. Our results also showed that inhibition of migration and invasion induced by DHEA in breast cancer cells is correlated with the decrease of cytokine/chemokine secretion and the diminution of tumor cells growth.  MCF-7 cells were the most responsive to the exposure to DHEA, whereas ZR-75-30 cells responded less to this hormone, suggesting that DHEA could be used in the treatment of breast cancer in early stages.

Association between PON1 genetic polymorphisms and miscarriage in Mexican women exposed to pesticides

BACKGROUND

Placental oxidative stress has been involved in the pathogenesis of certain reproductive adverse effects, including miscarriage. Paraxonase 1 (PON1) is a high-density lipoprotein(HDL)-linked enzyme that prevents oxidation of low-density lipoproteins (LDL) and is involved in detoxification from organophosphate pesticides.

OBJECTIVE

To assess the association between maternal PON1 polymorphisms (PON1192Q/R, PON155 L/M y PON1-108C/T) and the risk of miscarriage in women chronically exposed to organophosphate pesticides in Mexico.

METHODS

In a cross-sectional study, socio-demographic data, reproductive history data, environmental exposures, and other variables of concern were collected by means of a questionnaire from 264 women (floriculturists and wives of floriculturists) who had been pregnant sometime during the 10 years preceding the study. Blood samples were also collected from them. PON1192 and PON155 genotypes were determined by PCR amplification, and PON1-108 genotypes, by a TaqMan real-time polymerase chain reaction assay. Complete information regarding the results of pregnancy and maternal genotype tests was obtained for 514 pregnancies (35 miscarriages and 479 controls). The association between PON1 genotypes and miscarriage was evaluate through GEE models.

RESULTS

The risk of miscarriage by mothers with PON1192RR genotype was 2.2 higher than by mothers with PON1192QR/PON1192QQ genotype (95% CI 0.93-5.17). The risk was close to 4 times higher in mothers with PON155MM/PON155LM genotype than in mothers with PON155LL genotype (OR=3.9; 95% CI 1.38-11.0). No significant differences were found in risk of miscarriage based on the maternal PON1-108C/T genotype. No evidence was found of an interaction between the various PON1 genotypes and the mothers' floricultural activity during pregnancy.

CONCLUSIONS

This study suggests that there is an effect of genetic maternal PON1 polymorphisms on miscarriage and provides additional evidence that combines with the growing information about the ways in which certain PON1 genotypes can affect the development of the fetus in utero.

The interleukin-1 gene cluster polymorphisms are associated with Takayasu's arteritis in Mexican patients

Takayasu's arteritis (TA) is a chronic inflammatory arteritis of unknown etiology involving mainly the aorta and its major branches. The interleukin (IL) 1β and IL-1 receptor antagonist have been playing an important role as regulators of inflammation. We investigated whether the polymorphisms at the IL-1B and IL-1RN gene cluster were associated with the genetic susceptibility to develop TA. We analyzed the IL-1B, IL-1F10.3, and IL-1RN polymorphisms in a sample of 58 TA patients, and 248 clinically healthy unrelated Mexican individuals by 5' exonuclease TaqMan polymerase chain reaction. Polymorphic haplotypes were constructed after linkage disequilibrium analysis. We found increased frequencies of different polymorphisms (C allele and TC genotype of IL-1F10.3; TT genotype of IL-1RN.4; C allele and TC genotype of IL-1RN6.1; G allele of IL-1RN6.2 and haplotypes "1T" and "1C" of IL-RN VNTR and IL-1RN6.1) in the group of TA when compared to healthy controls. On the other hand, decreased frequency of IL-1-511 TC genotype was found in the TA group compared to controls. IL-1B and IL-1RN gene polymorphisms could be involved in the risk of developing TA in the Mexican population. These associations were independent of the affected vessels.

Detection of IS6110 and HupB gene sequences of Mycobacterium tuberculosis and bovis in the aortic tissue of patients with Takayasu's arteritis

BACKGROUND

Takayasu's arteritis (TA) is a chronic inflammatory disease affecting the large arteries and their branches; its etiology is still unknown. In individuals suffering from TA, arterial inflammation progresses to stenosis and/or occlusion, leading to organ damage and affecting survival. Relation of TA with Mycobacterium tuberculosis has been known, but there have been only a few systematic studies focusing on this association. The IS6110 sequence identifies the Mycobacterium tuberculosis complex and the HupB establishes the differences between M. tuberculosis and M. bovis. Our objective was to search the presence of IS6110 and HupB genes in aorta of patients with TA.

METHODS

We analyzed aorta tissues embedded in paraffin from 5760 autopsies obtained from our institution, we divided the selected samples as cases and controls;

CASES

aortic tissues of individuals with Takayasu's arteritis. Control positive: aortic tissues (with tuberculosis disease confirmed) and control negative with other disease aortic (atherosclerosis).

RESULTS

Of 181 selected aorta tissues, 119 fulfilled the corresponding criteria for TA, TB or atherosclerosis. Thus 33 corresponded to TA, 33 to tuberculosis (TB) and 53 to atherosclerosis. The mean age was 22 ± 13, 41 ± 19, and 57 ± 10, respectively. IS6110 and HupB sequences were detected in 70% of TA tissues, 82% in tuberculosis, and in 32% with atherosclerosis. Important statistical differences between groups with TA, tuberculosis versus atherosclerosis (p = 0.004 and 0.0001, respectively) were found.

CONCLUSION

We identified a higher frequency of IS6110 and HupB genes in aortic tissues of TA patients. This data suggests that arterial damage could occur due to previous infection with M. tuberculosis.

[Low paraoxonase and arylesterase plasma activities in Mexican patients with coronary artery disease]

PURPOSE

To determine the Paraoxonase-1 (PON1) activity as well as its pheno- and genotypes at position 192 in Mexican subjects with diagnosis of coronary heart disease (CHD).

METHODS

We determined the PON1-192 polymorphism by PCR-RFLP, and serum PON1 activity, using either paraoxon (PONase activity) or phenylacetate (ARE activity) as substrates, in 155 clinically healthy individuals (control group), and 155 patients with at least one myocardial infarction (CHD group). The biochemical A/B phenotype was determined by the ratio of the NaCI 1 M-stimulated PONase activity divided by the ARE activity.

RESULTS

We found significantly lower PONase and ARE activities in CHD patients as compared to controls (233.1 +/- 102.1 vs. 295.8 +/- 159.1 nmol/min/mL, and 103.1 +/- 33.7 vs 220.2 +/- 120.7 micromol/min/mL, respectively, p<0.05 for both). Allele and genotype frequencies for PON1-192 were similar in CHD patients and healthy controls. Moreover, in the control group, the PON1-192 Q/R genotype did not matched with the A/B phenotype as has been proposed by other studies.

CONCLUSIONS

There were important differences in the ARE and PONase activities between Mexican CHD patients and controls, suggesting that PON1 activity could be a good marker of CHD risk, whereas PON1-192 lacks of value to assess such risk.

Apolipoprotein E polymorphisms in Mexican patients with coronary artery disease

BACKGROUND

Apolipoprotein E polymorphisms have important effects on plasma lipid levels and in the genetic susceptibility to development of cardiovascular diseases. Thus, the purpose of this study was to investigate the association of apolipoprotein E polymorphisms with coronary artery disease and with plasma lipid levels in a group of Mexican Mestizo patients.

METHODS

Apolipoprotein E polymorphisms were determined in 156 Mexican patients with coronary artery disease and 200 non-related healthy controls using the restriction fragment length polymorphism technique. The correlation of these polymorphisms with lipid profile (total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol and triglycerides) in the patient group was determined.

RESULTS

A similar distribution of allele and genotype frequencies in coronary artery disease patients and healthy controls was found. Higher serum levels of high-density lipoprotein cholesterol and lower levels of low-density lipoprotein cholesterol, triglycerides and glucose were found in patients with the APOE*2/3 genotype when compared to patients with the APOE*3/4 and APOE*3/3 genotypes, although these differences were not significant.

CONCLUSIONS

Our data suggest that genetic variation at the APOE is not a genetic factor related to the genetic susceptibility to coronary artery disease in Mexican individuals, but the role of this polymorphism in determining the lipid profile cannot be excluded.

Angiotensin II upregulates LDL receptor-related protein (LRP1) expression in the vascular wall: a new pro-atherogenic mechanism of hypertension

AIMS

Hypertension is a risk factor for atherothrombotic vascular events. Angiotensin II (Ang II), one of the main vasoactive hormones of the renin-angiotensin system, has been associated with the development and progression of atherosclerosis. However, it is not fully known how Ang II contributes to lipid-enriched atherosclerotic lesion formation. In human vascular smooth muscle cells (VSMC), low density lipoprotein (LDL) receptor-related protein (LRP1) internalizes cholesteryl esters (CE) from extracellular matrix-bound aggregated LDL (agLDL). The aim of this study was to investigate the effect of Ang II on LRP1 expression and function in VSMC.

METHODS AND RESULTS

Here, we report for the first time that Ang II induces the upregulation of LRP1 expression in VSMC. Ang II (1 microM) induced maximal LRP1 mRNA expression at 12 h and maximal protein overexpression (by 4.10-fold) at 24 h in cultured human VSMC. Ang II effects were functionally translated into an increased CE accumulation from agLDL uptake (by two-fold at 50 microg/mL) that was prevented by the LRP1 ligand lactoferrin and by siRNA-LRP1 treatment. Ang II-LRP1 upregulation and excess CE accumulation from agLDL were prevented by losartan (an AT1 blocker) but not by PD123319 (a specific AT2 blocker). Additionally, in a normolipidaemic rat model, Ang II infusion produced a significant increase in aortic LRP1 expression and lipid infiltration in the arterial intima.

CONCLUSION

The in vitro and in vivo data reported here indicate that Ang II upregulates LRP1 receptor expression and LRP1-mediated aggregated LDL uptake in vascular cells.

Dehydroepiandrosterone Delays LDL Oxidation In Vitro and Attenuates Several oxLDL-Induced Inflammatory Responses in Endothelial Cells

Dehydroepiandrosterone (DHEA) has a protective role against atherosclerosis, most likely mediating an anti-inflammatory action. In order to understand the mechanisms involved in this protection, we evaluated the effects of DHEA on several molecules involved in the inflammatory response. Reactive oxygen species (ROS), expression of adhesion molecules, activation of the NF-kappaB/IkappaB-alpha pathway and of the AP-1 transcription factor were evaluated in human umbilical vein endothelial cells (HUVECs) treated with oxidized low density lipoproteins (oxLDL) and DHEA. We also determined if DHEA affected LDL oxidation in vitro. 100 microM DHEA-treatment inhibited the oxLDL-induced expression of ICAM-1, VCAM-1, PECAM-1, ROS production, and U937 cells adhesion to HUVECs. DHEA also delayed the kinetics of LDL oxidation in vitro. While DHEA did not affect the translocation of NF-kappaB neither the degradation IkappaB-alpha, it led to an increased translocation of AP-1. Our results suggest that DHEA inhibits the expression of molecules involved in the inflammatory process in endothelial cells activated with oxLDL, therefore its potential anti-inflammatory properties should be evaluated for the treatment of chronic inflammatory diseases such as atherosclerosis.

Abnormal HDL subclasses distribution in overweight children with insulin resistance or type 2 diabetes mellitus

BACKGROUND

Small HDL particles have emerged as significant predictors of incident type 2 diabetes mellitus (T2DM) in adults with impaired glucose tolerance (IGT). However, no previous study has investigated HDL size in pediatric subjects with these clinical conditions.

METHODS

We studied the HDL size distribution by native polyacrilamide gradient gel electrophoresis in 106 overweight children, 47 with T2DM, 43 with normal glucose tolerance (NGT), 16 with IGT, and 39 healthy weight controls.

RESULTS

Diabetic children had significantly lower proportions of HDL2b and HDL2a, and higher proportions of HDL3b and HDL3c than the other 3 groups. Overweight subjects showed HDL size distributions similar to those of controls. However, insulin-resistant children had lower proportions of HDL2b, and HDL2a, and higher proportions of HDL3b when compared with the insulin-sensitive overweight subjects. Multiple linear regression analyses showed that homeostasis model assessment correlated inversely with HDL2b and HDL2a, and directly with HDL3b, while BMI was independently associated only with HDL3a.

CONCLUSIONS

This study showed that HDL size distribution was shifted toward smaller particles in T2DM pediatric patients and in overweight children with insulin resistance, independent of their glucose tolerance status. Insulin resistance was the main factor associated with these HDL size abnormalities. This parameter could be useful as an early risk marker of incident diabetes and, probably, of coronary heart disease.

Contribution of cholesteryl ester transfer protein and lecithin:cholesterol acyltransferase to HDL size distribution

High-density lipoproteins (HDL) includes a heterogeneous class of lipoproteins grouped into various subclasses that seem to have different antiatherogenic function. Cholesteryl ester transfer protein (CETP) and lecithin cholesterol acyltransferase (LCAT) play an active role in HDL remodeling. This study was designed to define the role of CETP and LCAT activities on HDL-cholesterol (HDL-C) plasma levels and HDL size distribution, as determined by nondenaturating polyacrylamide gradient gel electrophoresis in 47 clinically healthy Mexican individuals without personal and family history of coronary heart disease. Surprisingly, plasma activities of CETP (29+/-4.1% of transfer) and LCAT (4.8+/-2.2% of esterification) did not correlate either with HDL-C plasma levels or with any other lipid parameter, indicating the poor contribution of these proteins to the lipid profile. The CETP activity showed a negative correlation with small HDL3b (r = -0476, P < 0.05), whereas LCAT was positively associated with this HDL subclass (r = 0.466, P < 0.05). The LCAT showed a negative correlation with large HDL2a (r = - 0.674, P < 0.005). Nevertheless, when the LCAT/CETP ratio was calculated, we observed that the higher the ratio, the greater the relative proportion of small HDL3b (r = 0.551, P < 0.05) and HDL3c (r = 0.477, P < 0.05). These results suggest that the balance of LCAT and CETP activities have a great impact in the plasma HDL size distribution.

Decreased activity of lecithin:cholesterol acyltransferase and hepatic lipase in chronic hypothyroid rats: implications for reverse cholesterol transport

Chronic hypothyroidism is frequently associated with atherosclerosis due to increased cholesterol plasma levels; nevertheless, the contribution of impaired reverse cholesterol transport (RCT) in this process has not been completely elucidated. The aim of this study was to evaluate the effect of thyroidectomy (Htx) upon the main stages of RCT in rats. Plasma lipid alterations induced by thyroidectomy showed a slight, but significant, reduction of total plasma triglycerides, a 300% increase of LDL-cholesterol and a 25% decrease in HDL-cholesterol compared to control rats. We evaluated the first stage of RCT determining 3H-cholesterol efflux in Fu5AH cells. The capacity of HDL obtained from Htx rats to promote cholesterol efflux was similar to that of controls. Lecithin:cholesterol acyltransferase (LCAT) activity, the second stage and the driving force of RCT was 30% lower in Htx animals compared to controls, as determined by reconstituted HDL used as an external substrate. Lipoproteins are remodeled by hepatic lipase; the mean activity of this enzyme in postheparin plasma of Htx animals was reduced by 30% compared to controls, thus suggesting an impaired HDL remodeling by this enzyme in the hypothyroid status. In contrast, lipoprotein lipase activity in the Htx group was unchanged. In summary, this study demonstrates that chronic hypothyroidism in the rat induced an impaired RCT mainly at the cholesterol esterification, and HDL remodeling mediated by hepatic lipase. The latter probably results in an abnormal HDL structure, i.e. phospholipid enrichment, which contributes to decrease HDL-apo AI fractional catabolic rates.

Chronic hypothyroidism induces abnormal structure of high-density lipoproteins and impaired kinetics of apolipoprotein A-I in the rat

Abnormal levels of plasma high-density lipoproteins (HDL) commonly reflect altered metabolism of the major HDL-apolipoprotein A-I (apo A-I). It is well known that thyroid hormones are involved in the regulation of lipoprotein metabolism, inducing significant changes in the concentration, size, and composition of plasma HDL. The purpose of this study was to evaluate the mechanisms responsible of the decreased HDL-apo A-I in chronic thyroidectomized rats (Htx) and to assess the role of HDL structure in apo A-I turnover. Htx rats were found to have a 3-fold increase in low-density lipoprotein-cholesterol (LDL-C), whereas HDL-C and apo A-I showed a 25.9% and 22.6% decrease compared to controls (P <.05), thus suggesting a defect in HDL metabolism. Turnover studies of apo A-I incorporated into normal HDL, using exogenous (125)I-radiolabeling, confirmed an altered fractional catabolic rate (FCR) in Htx rats (0.097 +/- 0.009 d(-1) v 0.154 +/- 0.026 d(-1) for Htx and control rats, respectively, P <.005). Apo A-I production rates calculated with autologous HDL data showed that apo A-I synthesis was decreased to a higher extent than the already reduced apo A-I catabolism, thus explaining the low apo A-I plasma levels in Htx rats. Composition analysis of HDL-Htx revealed increased phospholipid and apo E content, whereas apo A-IV was diminished. Such structural changes contribute to the reduced apo A-I catabolism as demonstrated with further kinetic turnover studies in normal rats treated with (125)I-radiolabeled apo A-I reincorporated into HDL isolated from plasma of Htx rats (FCR, 0.102 +/- 0.017 v 0.154 +/- 0.026 d(-1), for Htx and normal rats, respectively, P <.005). In summary, chronic hypothyroidism in rat a species that lacks cholesteryl ester transfer protein (CETP) activity is characterized by low HDL-C and apo A-I plasma levels as a result of a low apo A-I production rate that exceeds a decreased FCR. Both structural abnormalities of HDL and changes induced in the animal that affect HDL catabolism contribute to the low FCR of apo A-I in the hypothyroid state.