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1.
Ann Hematol ; 103(4): 1167-1179, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38386032

ABSTRACT

Ischemic stroke (IS) is one of the most impairing complications of sickle cell anemia (SCA), responsible for 20% of mortality in patients. Rheological alterations, adhesive properties of sickle reticulocytes, leukocyte adhesion, inflammation and endothelial dysfunction are related to the vasculopathy observed prior to ischemic events. The role of the vascular endothelium in this complex cascade of mechanisms is emphasized, as well as in the process of ischemia-induced repair and neovascularization. The aim of the present study was to perform a comparative transcriptomic analysis of endothelial colony-forming cells (ECFCs) from SCA patients with and without IS. Next, to gain further insights of the biological relevance of differentially expressed genes (DEGs), functional enrichment analysis, protein-protein interaction network (PPI) construction and in silico prediction of regulatory factors were performed. Among the 2469 DEGs, genes related to cell proliferation (AKT1, E2F1, CDCA5, EGFL7), migration (AKT1, HRAS), angiogenesis (AKT1, EGFL7) and defense response pathways (HRAS, IRF3, TGFB1), important endothelial cell molecular mechanisms in post ischemia repair were identified. Despite the severity of IS in SCA, widely accepted molecular targets are still lacking, especially related to stroke outcome. The comparative analysis of the gene expression profile of ECFCs from IS patients versus controls seems to indicate that there is a persistent angiogenic process even after a long time this complication has occurred. Thus, this is an original study which may lead to new insights into the molecular basis of SCA stroke and contribute to a better understanding of the role of endothelial cells in stroke recovery.


Subject(s)
Anemia, Sickle Cell , Stroke , Humans , Endothelial Cells/metabolism , Transcriptome , Stroke/genetics , Stroke/complications , Anemia, Sickle Cell/complications , Ischemia , Gene Expression Profiling , Calcium-Binding Proteins/genetics , Calcium-Binding Proteins/metabolism , EGF Family of Proteins/genetics , EGF Family of Proteins/metabolism
2.
Exp Biol Med (Maywood) ; 248(8): 677-684, 2023 04.
Article in English | MEDLINE | ID: mdl-37012663

ABSTRACT

Among sickle cell anemia (SCA) complications, proliferative sickle cell retinopathy (PSCR) is one of the most important, being responsible for visual impairment in 10-20% of affected eyes. The aim of this study was to identify differentially expressed genes (DEGs) present in pathways that may be implicated in the pathophysiology of PSCR from the transcriptome profile analysis of endothelial progenitor cells. RNA-Seq was used to compare gene expression profile of circulating endothelial colony-forming cells (ECFCs) from HbSS patients with and without PSCR. Furthermore, functional enrichment analysis and protein-protein interaction (PPI) networks were performed to gain further insights into biological functions. The differential expression analysis identified 501 DEGs, when comparing the groups with and without PSCR. Furthermore, functional enrichment analysis showed associations of the DEGs in 200 biological processes. Among these, regulation of mitogen-activated protein (MAP) kinase activity, positive regulation of phosphatidylinositol 3-kinase (PI3K), and positive regulation of Signal Transducer and Activator of Transcription (STAT) receptor signaling pathway were observed. These pathways are associated with angiogenesis, cell migration, adhesion, differentiation, and proliferation, important processes involved in PSCR pathophysiology. Moreover, our results showed an over-expression of VEGFC (vascular endothelial growth factor-C) and FLT1 (Fms-Related Receptor Tyrosine Kinase 1) genes, when comparing HbSS patients with and without PSCR. These results may indicate a possible association between VEGFC and FLT1 receptor, which may activate signaling pathways such as PI3K/AKT and MAPK/ERK and contribute to the mechanisms implicated in neovascularization. Thus, our findings contain preliminary results that may guide future studies in the field, since the molecular mechanisms of PSCR are still poorly understood.


Subject(s)
Endothelial Progenitor Cells , Retinal Diseases , Humans , Endothelial Progenitor Cells/metabolism , Transcriptome/genetics , Vascular Endothelial Growth Factor C/metabolism , Phosphatidylinositol 3-Kinases/metabolism , Gene Expression Profiling
3.
Ophthalmic Genet ; 44(3): 246-252, 2023 06.
Article in English | MEDLINE | ID: mdl-36994723

ABSTRACT

BACKGROUND: Primary open-angle glaucoma (POAG), the world's main cause of irreversible blindness, is an asymptomatic and neurodegenerative disease of multifactorial etiology with ethnic and geographic disparities. Multiethnic genome-wide association studies (GWAS) identified single nucleotide variants (SNVs) in ATXN2, FOXC1, and TXNRD2 loci as risk factors for POAG pathophysiology and/or endophenotypes. The aim of this case-control study was to investigate the association of the variants rs7137828 (ATXN2), rs2745572 (FOXC1), and rs35934224 (TXNRD2), as risk factors for POAG development, additionally to rs7137828 association with glaucoma clinical parameters in a Brazilian cohort from the Southeast and South regions. METHODS: This investigation comprised 506 cases and 501 controls. Variants rs2745572 and rs35934224 were genotyped through TaqMan® assays and validated by Sanger sequencing. Variant rs7137828 was genotyped exclusively by Sanger sequencing. RESULTS: The primary research outcome revealed that the variant rs7137828 (ATXN2) was associated with an increased risk for the development of POAG in the presence of the TT genotype compared to the CC genotype (p = 0.006; Odds Ratio [OR] = 1.717; Confidence Interval [CI] 95% = 1.169-2.535). There was no significant association of rs2745572 and rs35934224 genotypes with POAG. The CT genotype of the rs7137828 was associated with the vertical cup-to-disk ratio (VCDR) (p = .023) but not with the age at diagnosis or the mean deviation. CONCLUSION: Our data indicate the rs7137828 associated with increased risk for the development of POAG and VCDR in a Brazilian cohort. If validated in additional populations, these findings may enable the development of relevant strategies for early diagnosis of glaucoma in the future.


Subject(s)
Glaucoma, Open-Angle , Neurodegenerative Diseases , Humans , Glaucoma, Open-Angle/genetics , Glaucoma, Open-Angle/diagnosis , Genome-Wide Association Study , Case-Control Studies , Brazil/epidemiology , Genotype , Risk Factors , Polymorphism, Single Nucleotide , Genetic Predisposition to Disease , Forkhead Transcription Factors/genetics , Ataxin-2/genetics , Thioredoxin Reductase 2/genetics
4.
PLoS One ; 17(9): e0274762, 2022.
Article in English | MEDLINE | ID: mdl-36129958

ABSTRACT

Pregnancy in Sickle Cell Disease (SCD) women is associated to increased risk of clinical and obstetrical complications. Placentas from SCD pregnancies can present increased abnormal findings, which may lead to placental insufficiency, favoring adverse perinatal outcome. These placental abnormalities are well known and reported, however little is known about the molecular mechanisms, such as epigenetics. Thus, our aim was to evaluate the DNA methylation profile in placentas from women with SCD (HbSS and HbSC genotypes), compared to uncomplicated controls (HbAA). We included in this study 11 pregnant women with HbSS, 11 with HbSC and 21 with HbAA genotypes. Illumina Methylation EPIC BeadChip was used to assess the whole placental DNA methylation. Pyrosequencing was used for array data validation and qRT-PCR was applied for gene expression analysis. Our results showed high frequency of hypermethylated CpGs sites in HbSS and HbSC groups with 73.5% and 76.2% respectively, when compared with the control group. Differentially methylated regions (DMRs) also showed an increased hypermethylation status for the HbSS (89%) and HbSC (86%) groups, when compared with the control group methylation data. DMRs were selected for methylation validation (4 DMRs-HbSS and 3 DMRs the HbSC groups) and after analyses three were validated in the HbSS group, and none in the HbSC group. The gene expression analysis showed differential expression for the PTGFR (-2.97-fold) and GPR56 (3.0-fold) genes in the HbSS group, and for the SPOCK1 (-2.40-fold) and ADCY4 (1.80-fold) genes in the HbSC group. Taken together, these data strongly suggest that SCD (HbSS and HbSC genotypes) can alter placental DNA methylation and lead to gene expression changes. These changes possibly contribute to abnormal placental development and could impact in the clinical course, especially for the fetus, possibly leading to increased risk of abortion, fetal growth restriction (FGR), stillbirth, small for gestational age newborns and prematurity.


Subject(s)
Anemia, Sickle Cell , Hemoglobin SC Disease , Anemia, Sickle Cell/complications , Anemia, Sickle Cell/genetics , Epigenesis, Genetic , Female , Hemoglobin SC Disease/genetics , Hemoglobin, Sickle/genetics , Humans , Infant, Newborn , Placenta/metabolism , Pregnancy , Proteoglycans/metabolism
5.
G3 (Bethesda) ; 12(7)2022 07 06.
Article in English | MEDLINE | ID: mdl-35511163

ABSTRACT

Admixture is known to greatly impact the genetic landscape of a population and, while genetic variation underlying human phenotypes has been shown to differ among populations, studies on admixed subjects are still scarce. Latin American populations are the result of complex demographic history, such as 2 or 3-way admixing events, bottlenecks and/or expansions, and adaptive events unique to the American continent. To explore the impact of these events on the genetic structure of Latino populations, we evaluated the following haplotype features: linkage disequilibrium, shared identity by descent segments, runs of homozygosity, and extended haplotype homozygosity (integrated haplotype score) in Latinos represented in the 1000 Genome Project along with array data from 171 Brazilians sampled in the South and Southeast regions of Brazil. We found that linkage disequilibrium decay relates to the amount of American and African ancestry. The extent of identity by descent sharing positively correlates with historical effective population sizes, which we found to be steady or growing, except for Puerto Ricans and Colombians. Long runs of homozygosity, a particular instance of autozygosity, was only enriched in Peruvians and Native Americans. We used simulations to account for random sampling and linkage disequilibrium to filter positive selection indexes and found 244 unique markers under selection, 26 of which are common to 2 or more populations. Some markers exhibiting positive selection signals had estimated time to the most recent common ancestor consistent with human adaptation to the American continent. In conclusion, Latino populations present highly divergent haplotype characteristics that impact genetic architecture and underlie complex phenotypes.


Subject(s)
Genetics, Population , Hispanic or Latino , Brazil , Demography , Haplotypes , Hispanic or Latino/genetics , Humans , Linkage Disequilibrium , Polymorphism, Single Nucleotide
6.
Mol Vis ; 28: 1-10, 2022.
Article in English | MEDLINE | ID: mdl-35400990

ABSTRACT

Purpose: Glaucoma is the world's leading cause of irreversible blindness, with primary open-angle glaucoma (POAG) being the most prevalent subtype. In recent years, there have been advances in knowledge about the genetics involved in POAG, but genetic studies in admixed populations, such as Brazilians, are still rare. This study aimed to evaluate the association of single nucleotide variants (SNV) of the ABCA1 (rs2472493) and GAS7 (rs9913911) genes with POAG in a sample of the Brazilian population. Furthermore, the study aimed to evaluate the relationship between these SNVs and the need for surgical intervention in glaucoma control. Methods: A cross-sectional association study with 1,009 subjects (505 patients with POAG and 504 controls) was performed. Participants underwent a comprehensive ocular examination, including the need for surgical procedures for intraocular pressure control. Genotyping of SNVs was performed using the TaqMan genotyping assay. Results: SNV rs9913911 of GAS7 was found to be associated with POAG in the presence of the risk allele A (p = 0.0004) and the AA genotype (p = 0.002). There was no association between SNV rs2472493 of ABCA1 for either the allele risk or genotypes. However, the combination of these variants showed an additive effect on the risk for POAG: ABCA1(GG) + GAS7(AA; p = 0.02), ABCA1(GG) + GAS7(AG; p = 0.003), and ABCA1(AG) + GAS7(AG; p = 0.004). Also, POAG patients carrying the AA genotype of the GAS7 gene required antiglaucomatous surgery more frequently than those without the AA genotype (p = 0.01). Conclusions: In a Brazilian population sample, there was an association identified between SNV rs9913911 (GAS7) and the risk of POAG, and an additive effect was found when GAS7 was combined with SNV rs2472493 (ABCA1). There was an association between SNV rs9913911 (GAS7) and the risk for antiglaucomatous surgery.


Subject(s)
Glaucoma, Open-Angle , Glaucoma , ATP Binding Cassette Transporter 1/genetics , Brazil , Cross-Sectional Studies , Genetic Predisposition to Disease , Genotype , Glaucoma/genetics , Glaucoma, Open-Angle/genetics , Humans , Intraocular Pressure , Nerve Tissue Proteins/genetics , Polymorphism, Single Nucleotide/genetics
7.
Sci Rep ; 12(1): 286, 2022 01 07.
Article in English | MEDLINE | ID: mdl-34997134

ABSTRACT

Pterygium is a common ocular surface condition frequently associated with irritative symptoms. The precise identity of its critical triggers as well as the hierarchical relationship between all the elements involved in the pathogenesis of this disease are not yet elucidated. Meta-analysis of gene expression studies represents a novel strategy capable of identifying key pathogenic mediators and therapeutic targets in complex diseases. Samples from nine patients were collected during surgery after photo documentation and clinical characterization of pterygia. Gene expression experiments were performed using Human Clariom D Assay gene chip. Differential gene expression analysis between active and atrophic pterygia was performed using limma package after adjusting variables by age. In addition, a meta-analysis was performed including recent gene expression studies available at the Gene Expression Omnibus public repository. Two databases including samples from adults with pterygium and controls fulfilled our inclusion criteria. Meta-analysis was performed using the Rank Production algorithm of the RankProd package. Gene set analysis was performed using ClueGO and the transcription factor regulatory network prediction was performed using appropriate bioinformatics tools. Finally, miRNA-mRNA regulatory network was reconstructed using up-regulated genes identified in the gene set analysis from the meta-analysis and their interacting miRNAs from the Brazilian cohort expression data. The meta-analysis identified 154 up-regulated and 58 down-regulated genes. A gene set analysis with the top up-regulated genes evidenced an overrepresentation of pathways associated with remodeling of extracellular matrix. Other pathways represented in the network included formation of cornified envelopes and unsaturated fatty acid metabolic processes. The miRNA-mRNA target prediction network, also reconstructed based on the set of up-regulated genes presented in the gene ontology and biological pathways network, showed that 17 target genes were negatively correlated with their interacting miRNAs from the Brazilian cohort expression data. Once again, the main identified cluster involved extracellular matrix remodeling mechanisms, while the second cluster involved formation of cornified envelope, establishment of skin barrier and unsaturated fatty acid metabolic process. Differential expression comparing active pterygium with atrophic pterygium using data generated from the Brazilian cohort identified differentially expressed genes between the two forms of presentation of this condition. Our results reveal differentially expressed genes not only in pterygium, but also in active pterygium when compared to the atrophic ones. New insights in relation to pterygium's pathophysiology are suggested.


Subject(s)
Gene Expression Profiling , Gene Regulatory Networks , MicroRNAs/genetics , Pterygium/genetics , RNA, Messenger/genetics , Transcriptome , Adult , Aged , Databases, Genetic , Female , Gene Expression Regulation , Humans , Male , Middle Aged , Oligonucleotide Array Sequence Analysis , Pterygium/physiopathology , Pterygium/surgery
8.
Ophthalmic Genet ; 42(5): 533-538, 2021 10.
Article in English | MEDLINE | ID: mdl-34132166

ABSTRACT

Background: Age-related macular degeneration (AMD) is a multifactorial disease and one of the main causes of blindness in people over 50 years old. The etiology and pathophysiology of AMD are not well understood. The aim of this study was to investigate whether the rs1143627 variant allele of IL1B, which encodes Interleukin (IL)-1ß, a key cytokine, mediates immune and inflammatory responses.Methods: A case-control study was conducted with 397 AMD patients and 402 controls in Brazil. IL1B genotyping was carried out with TaqMan® genotyping assay. Differences in IL1B allele frequencies and genotypes were evaluated between patients and controls and between wet and dry subgroups of AMD. Relationships between allele presence/genotype and disease risk are reported as odds ratios (ORs) with 95% confidence intervals (CIs).Results: Genotype proportions for the rs1143627 variant allele of IL1B were similar between AMD patients and controls (p = .21), with 84.38% of AMD patients and 79.60% of the controls carrying the variant allele. We observed a trend toward the variant allele being associated with AMD risk (OR = 1.38, 95% CI 0.95-2.03, p = .08), as well as a trend toward the variant allele being associated with increased risk for wet AMD in particular (OR = 1.23, 95% CI 0.96-1.56, p = .08).Conclusions: The rs1443627 variant was not associated with AMD risk in this Brazilian population sample. Larger studies are warranted to determine whether the trends observed in this study reflect a relationship between this variant and risk of AMD, especially wet AMD.


Subject(s)
Interleukin-1beta/genetics , Macular Degeneration/genetics , Polymorphism, Single Nucleotide/genetics , Aged , Aged, 80 and over , Brazil/epidemiology , Case-Control Studies , Female , Gene Frequency , Genotyping Techniques , Humans , Macular Degeneration/epidemiology , Male , Middle Aged , Odds Ratio , Ophthalmoscopy , Risk Factors , Slit Lamp Microscopy , Tomography, Optical Coherence , Visual Acuity/physiology
9.
Ophthalmic Genet ; 42(1): 53-61, 2021 02.
Article in English | MEDLINE | ID: mdl-33287609

ABSTRACT

Background: Primary open-angle glaucoma (POAG) is a multifactorial disease that affects 65.5 million people worldwide. In addition to the genetic variants already established as indicators of greater risk for POAG, the apolipoprotein (APOE) gene has been studied in some populations, with controversial results. The aim of this study is to investigate the frequency of the genetic variants of APOE in the Brazilian population, and to evaluate the association between these polymorphisms and the risk of POAG. Methods: APOE variants (rs429358; rs7412) were genotyped in 402 POAG patients and 401 controls. We evaluated the association between APOE genetic variants and the risk for POAG, as well as the correlation between the requirement of glaucoma surgery and the APOE polymorphisms. Results: Among the three APOE gene isoforms, we found a low frequency of APOE alleles ε2 (7.34%) and ε4 (11.76%), but a high frequency of ε3 (80.88%) in our population. When compared to ε3ε3 reference genotype, ε2 allele-carriers (OR = 1.516; p-value = 0.04) and ε2ε3 genotype (OR = 1.655; p-value = 0.02) were associated with a greater risk for POAG. An additive genetic model confirmed the influence of the ε2 allele in the risk of POAG in this sample of the Brazilian population (OR = 1.502; p-value = 0.04). There was no significant association between the analyzed genotypes and the requirement or number of glaucoma surgeries (p > .05). Conclusion: Brazilian individuals carrying the APOEε2 allele may be at an increased risk for the development of POAG.


Subject(s)
Apolipoproteins E/genetics , Genetic Predisposition to Disease , Glaucoma, Open-Angle/pathology , Polymorphism, Single Nucleotide , Adult , Aged , Aged, 80 and over , Brazil/epidemiology , Case-Control Studies , Female , Genotype , Glaucoma, Open-Angle/epidemiology , Glaucoma, Open-Angle/genetics , Humans , Male , Middle Aged
10.
Blood Cells Mol Dis ; 84: 102458, 2020 09.
Article in English | MEDLINE | ID: mdl-32562953

ABSTRACT

Sickle cell disease (SCD) is a group of disorders whose common characteristic is the presence of hemoglobin (Hb) S in erythrocytes. The main consequence of this abnormality is vaso-occlusion, which can affect almost all organs including the placenta. This study aimed to evaluate the gene expression profile in placentas of women with SCD by means of total RNA sequencing. For this, we proposed a case-control study, with three groups of pregnant women: HbSS (n = 10), HbSC (n = 14) and HbAA (n = 21). The results showed differences in expression in a number of genes such as NOS2 (fold change, FC = 4.52), HLAG (FC = 5.56), ASCL2 (FC = 3.61), CXCL10 (FC = -3.66) and IL1R2 (FC = 3.92) for the HbSC group and S100A8 (FC = -3.82), CPXM2 (FC = 4.57), CXCL10 (FC = -4.59), CXCL11 (FC = -3.72) and CAMP (FC = -4.55) for the HbSS group. Differentially expressed genes are mainly associated with migration, trophoblast differentiation and inflammation. The causes leading to altered gene expression in placentas of sickle cell patients are not fully understood, but the presence of intravascular hemolysis and vaso-occlusion, with cycles of ischemia and reperfusion, may contribute to the emergence of an environment which can be very harmful for placental physiology, altering the nutrient supply and metabolic exchange for fetal growth.


Subject(s)
Anemia, Sickle Cell/genetics , Placenta/metabolism , Pregnancy Complications, Hematologic/genetics , Transcriptome , Adult , Case-Control Studies , Cell Differentiation , Cell Movement , Cells, Cultured , Female , Humans , Inflammation/genetics , Pregnancy , Trophoblasts/cytology , Trophoblasts/metabolism
11.
Arq. bras. oftalmol ; 82(6): 528-536, Nov.-Dec. 2019. tab, graf
Article in English | LILACS | ID: biblio-1038700

ABSTRACT

ABSTRACT Pterygium pathogenesis has been mainly asso ciated with UV light exposure; however, this association remains quite controversial. The complete mechanism of pterygium also remains to be clarified. Factors such as inflammation, viral infection, oxidative stress, DNA methylation, inflammatory mediators, extracellular matrix modulators, apoptotic and oncogenic proteins, loss of heterozygosity, microsatellite instability, lymphangiogenesis, epithelial-mesenchymal cell transition, and alterations in cholesterol metabolism have been identified as causes. Several studies aimed to clarify the molecular mechanisms underlying the growth and proliferation of pterygium. Understanding its molecular basis provides new potential therapeutic targets for its prevention and treatment. A comprehensive search of the databases, namely, MedLine, EMBASE, and LILACS, was conducted with the following key words: pterygium, epidemiology, pathogenesis, biomarkers, and review. This review describes the epidemiology, clinical presentation, and current investigation of biological mediators involved in pterygium development.


RESUMO A patogênese do pterígio tem sido relacionada, prin cipalmente, à exposição à luz ultravioleta, mas esta asso ciação permanece bastante controversa. O mecanismo completo do pte rígio também permanece por esclarecer. Fatores como inflamação, infecção viral, estresse oxidativo, metilação do DNA, mediadores inflamatórios, moduladores de matriz extracelular, proteínas apoptóticas e oncogênicas, perda de heterozigose, instabilidade de microssatélites, linfangiogênese, transição celular epitelial-mesenquimal e alterações no metabolismo do colesterol tem sido identificados como causas. Diversos estudos visam esclarecer os mecanismos moleculares subjacentes ao crescimento e proliferação do pterígio. Entender sua base mo lecular fornece novos alvos terapêuticos potenciais para sua prevenção e tratamento. Uma busca abrangente nas bases de dados, a saber, MedLine, EMBASE e LILACS, foi realizada com as seguintes palavras-chave: pterígio; epidemiologia; patogênese; biomarcadores e revisão. Esta revisão descreve a epidemiologia, apresentação clínica e a atual investigação de mediadores biológicos envolvidos no desenvolvimento do pterígio.


Subject(s)
Humans , Male , Female , Pterygium/genetics , Pterygium/metabolism , Genetic Markers , Gene Expression , Genes, Tumor Suppressor , Apoptosis Regulatory Proteins , Extracellular Matrix
12.
Arq Bras Oftalmol ; 82(6): 528-536, 2019.
Article in English | MEDLINE | ID: mdl-31576927

ABSTRACT

Pterygium pathogenesis has been mainly asso ciated with UV light exposure; however, this association remains quite controversial. The complete mechanism of pterygium also remains to be clarified. Factors such as inflammation, viral infection, oxidative stress, DNA methylation, inflammatory mediators, extracellular matrix modulators, apoptotic and oncogenic proteins, loss of heterozygosity, microsatellite instability, lymphangiogenesis, epithelial-mesenchymal cell transition, and alterations in cholesterol metabolism have been identified as causes. Several studies aimed to clarify the molecular mechanisms underlying the growth and proliferation of pterygium. Understanding its molecular basis provides new potential therapeutic targets for its prevention and treatment. A comprehensive search of the databases, namely, MedLine, EMBASE, and LILACS, was conducted with the following key words: pterygium, epidemiology, pathogenesis, biomarkers, and review. This review describes the epidemiology, clinical presentation, and current investigation of biological mediators involved in pterygium development.


Subject(s)
Pterygium/genetics , Pterygium/metabolism , Apoptosis Regulatory Proteins , Extracellular Matrix , Female , Gene Expression , Genes, Tumor Suppressor , Genetic Markers , Humans , Male
13.
Sci Rep ; 9(1): 10896, 2019 07 26.
Article in English | MEDLINE | ID: mdl-31350437

ABSTRACT

Genetic analysis of admixed populations raises special concerns with regard to study design and data processing, particularly to avoid population stratification biases. The point mutation responsible for sickle cell anaemia codes for a variant hemoglobin, sickle hemoglobin or HbS, whose presence drives the pathophysiology of disease. Here we propose to explore ancestry and population structure in a genome-wide study with particular emphasis on chromosome 11 in two SCA admixed cohorts obtained from urban populations of Brazil (Pernambuco and São Paulo) and the United States (Pennsylvania). Ancestry inference showed different proportions of European, African and American backgrounds in the composition of our samples. Brazilians were more admixed, had a lower African background (43% vs. 78% on the genomic level and 44% vs. 76% on chromosome 11) and presented a signature of positive selection and Iberian introgression in the HbS region, driving a high differentiation of this locus between the two cohorts. The genetic structures of the SCA cohorts from Brazil and US differ considerably on the genome-wide, chromosome 11 and HbS mutation locus levels.


Subject(s)
Anemia, Sickle Cell/genetics , Chromosomes, Human, Pair 11/genetics , Genetics, Population/methods , Genotype , Hemoglobin, Sickle/genetics , Population Groups , Racial Groups/genetics , Brazil , Cohort Studies , Gene Frequency , Genome , Genome-Wide Association Study , Haplotypes , Humans , United States
15.
PLoS One ; 13(11): e0207409, 2018.
Article in English | MEDLINE | ID: mdl-30444892

ABSTRACT

The aim of this study was to estimate the age of the Cys433Arg (c.1297T>C, p.Cys433Arg) variant by comparing the genotypes of individuals affected and not affected by primary open angle glaucoma juvenile onset (JOAG). Our sample consisted of 35 JOAG-affected individuals from three families, 16 unrelated patients with the MYOC p.Cys433Arg variant and 16 unaffected individuals. Genomic DNA was amplified by PCR; nine short tandem repeats were genotyped through automated electrophoresis and three single nucleotide polymorphisms through Sanger sequencing. The determination of haplotypes was performed using Arlequin software and age estimation was performed using DMLE+ 2.3 and BDMC21 softwares. Four markers constituted the haplotypes associated with the p.Cys433Arg variant. The software DMLE+2.3 predicted an age of 43 generations for this variant with a 95% confidence interval ranging from 28 to 76 generations (560-1520 years) and BDMC21 predicted an age of 59 generations (1180 years) (95% CI: 40 to 100).


Subject(s)
Cytoskeletal Proteins/genetics , Eye Proteins/genetics , Genotype , Glaucoma, Open-Angle/genetics , Glycoproteins/genetics , Mutation, Missense , Polymorphism, Single Nucleotide , Adult , Amino Acid Substitution , Brazil/epidemiology , Female , Glaucoma, Open-Angle/epidemiology , Humans , Male
16.
Ophthalmic Genet ; 39(6): 717-724, 2018 12.
Article in English | MEDLINE | ID: mdl-30484747

ABSTRACT

BACKGROUND: The purpose of this study was to screen juvenile open angle glaucoma (JOAG) patients from Brazil for variants within the MYOC and CYP1B1 genes. MATERIAL AND METHODS: In this study, we evaluated the coding regions of MYOC and CYP1B1 genes in 100 non-related patients with JOAG and 200 controls through Sanger sequencing. We also tested the most frequent single nucleotide variants of CYP1B1 for association with JOAG. RESULTS: Sixteen different sequence variants in the MYOC gene were observed in JOAG patients: eight variants were described as neutral and eight were identified in 34 out of 100 patients with JOAG and no controls, thus being considered damaging. In the CYP1B1 gene, nine neutral variants and two damaging alterations were found among JOAG patients. No association between CYP1B1 variants and JOAG was detected. CONCLUSION: While MYOC damaging alterations were highly prevalent (34%), CYP1B1 damaging variants were less frequent (2%) in this cohort of Brazilian JOAG patients.


Subject(s)
Cytochrome P-450 CYP1B1/genetics , Cytoskeletal Proteins/genetics , Eye Proteins/genetics , Genetic Variation , Glaucoma, Open-Angle/genetics , Glycoproteins/genetics , Adult , Brazil/epidemiology , Cohort Studies , Exons/genetics , Female , Glaucoma, Open-Angle/diagnosis , Glaucoma, Open-Angle/epidemiology , Gonioscopy , Humans , Intraocular Pressure , Male , Mutation , Real-Time Polymerase Chain Reaction , Visual Acuity
17.
Ophthalmic Genet ; 39(1): 46-50, 2018.
Article in English | MEDLINE | ID: mdl-28846052

ABSTRACT

Age-related macular degeneration is a multifactorial disease that can lead to vision impairment in older individuals. Although the etiology of age-related macular degeneration remains unknown, risk factors include age, ethnicity, smoking, hypertension, obesity, and genetic factors. Two main loci have been identified through genome-wide association studies, on chromosomes 1 and 10. Among the variants located at the 10q26 region, rs11200638, located at the HTRA1 gene promoter, has been associated with age-related macular degeneration in several populations and is considered the main polymorphism. We conducted a replication case-control study to analyze the frequency and participation of rs11200638 in the etiology of age-related macular degeneration in a sample of patients and controls from the State of São Paulo, Brazil, through polymerase chain reaction and enzymatic digestion. The frequency of the A allele was 57.60% in patients with age-related macular degeneration and 36.45% in controls (p value < 1e-07), representing a 2.369-fold higher risk factor for the disease. Both the AA and AG genotypes were observed more frequently in the age-related macular degeneration group compared to the control group (p = 1.21e-07 and 0.0357, respectively). No statistically significant results were observed after stratification in dry versus wet types or advanced versus non-advanced forms. To our knowledge, this is the first time the association between rs11200638 and overall age-related macular degeneration has been reported in South America.


Subject(s)
Geographic Atrophy/genetics , High-Temperature Requirement A Serine Peptidase 1/genetics , Polymorphism, Single Nucleotide , Wet Macular Degeneration/genetics , Aged , Brazil/epidemiology , Case-Control Studies , Chromosomes, Human, Pair 10/genetics , Female , Gene Frequency , Genetic Association Studies , Geographic Atrophy/ethnology , Humans , Male , Polymerase Chain Reaction , Wet Macular Degeneration/ethnology
18.
Ophthalmic Genet ; 39(2): 194-199, 2018 04.
Article in English | MEDLINE | ID: mdl-29111846

ABSTRACT

Large-scale genome-wide association studies have identified several susceptibility variants associated with the risk of primary open-angle glaucoma (POAG), among which rs4236601 (CAV1/CAV2) at chromosome 7q31 and rs2157719 at chromosome 9p21 (CDKN2B-AS1). The purpose of this study was to investigate whether these variants contribute to the incidence of POAG in a sample of the Brazilian Southeastern population and to determine the best-fitted genetic model for these single nucleotide polymorphisms (SNPs). A case-control study with 557 individuals, 310 with POAG, and 247 controls was conducted through PCR and direct sequencing. We observed a significant effect of the heterozygous genotype (G/A) of rs2157719 that occurred more frequently in the control group (p = 0.0004; OR: 0.517, CI 95%: 0.357-0.745). Allele frequencies also differed between cases and controls (p = 0.006; OR: 0.694, CI 95%: 0.522-0.922) with the best-fitted genetic model for rs2157719 being the codominant model. No differences were observed for genotype and allele distributions in relation to rs4236601 in the CAV1/CAV2 region. The association of rs2157719 (CDKN2B-AS1) with the POAG phenotype corroborates previously published results, reinforcing the importance of this variant in POAG etiology.


Subject(s)
Caveolin 1/genetics , Caveolin 2/genetics , Glaucoma, Open-Angle/genetics , Polymorphism, Single Nucleotide , RNA, Long Noncoding/genetics , Adult , Aged , Aged, 80 and over , Brazil , Case-Control Studies , Female , Gene Frequency , Genetic Predisposition to Disease , Genome-Wide Association Study , Genotype , Glaucoma, Open-Angle/diagnosis , Humans , Intraocular Pressure , Male , Middle Aged
19.
Neuroophthalmology ; 41(2): 99-102, 2017 Apr.
Article in English | MEDLINE | ID: mdl-28348633

ABSTRACT

Glaucoma is a neurodegenerative disorder characterized by thinning of neuroretinal rim, enlarged cup-to-disc ratio (CDR) and visual field damage. Although raised intraocular pressure is main risk factor for development of glaucoma, it can occur with consistently normal measurements in the intraocular pressure as normal tension glaucoma (NTG). Enlargement of CDR is a classical sign of glaucoma, but it can also result from non-glaucomatous optic neuropathies such as Leber hereditary optic neuropathy (LHON). We describe a case of LHON with increased CDR, discuss its differential diagnosis with NTG and highlight the reasons for misdiagnoses between these two entities.

20.
Ann Hematol ; 95(11): 1859-67, 2016 Oct.
Article in English | MEDLINE | ID: mdl-27546026

ABSTRACT

Sickle cell disease (SCD) is a complex disease that is characterized by the polymerization of deoxyhemoglobin S, altered red blood cell membrane biology, endothelial activation, hemolysis, a procoagulant state, acute and chronic inflammation, and vaso-occlusion. Among the physiological changes that occur during pregnancy, oxygen is consumed by fetal growth, and pregnant women with SCD are more frequently exposed to low oxygen levels. This might lead to red blood cells sickling, and, consequently, to vaso-occlusion. The mechanisms by which SCD affects placental physiology are largely unknown, and chronic inflammation might be involved in this process. This study aimed to evaluate the gene expression profile of inflammatory response mediators in the placentas of pregnant women with sickle cell cell anemia (HbSS) and hemoglobinopathy SC (HbSC). Our results show differences in a number of these genes. For the HbSS group, when compared to the control group, the following genes showed differential expression: IL1RAP (2.76-fold), BCL6 (4.49-fold), CXCL10 (-2.12-fold), CXCR1 (-3.66-fold), and C3 (-2.0-fold). On the other hand, the HbSC group presented differential expressions of the following genes, when compared to the control group: IL1RAP (4.33-fold), CXCL1 (3.05-fold), BCL6 (4.13-fold), CXCL10 (-3.32-fold), C3 (-2.0-fold), and TLR3 (2.38-fold). Taken together, these data strongly suggest a differential expression of several inflammatory genes in both SCD (HbSS and HbSC), indicating that the placenta might become an environment with hypoxia, and increased inflammation, which could lead to improper placental development.


Subject(s)
Anemia, Sickle Cell/genetics , Cytokines/biosynthesis , Gene Expression Regulation , Hemoglobin SC Disease/genetics , Inflammation/genetics , Placenta/metabolism , Pregnancy Complications, Hematologic/genetics , Receptors, Cytokine/biosynthesis , Adult , Anemia, Sickle Cell/complications , Case-Control Studies , Cytokines/genetics , Female , Gene Expression Profiling , Hemoglobin SC Disease/complications , Humans , Inflammation/etiology , Placenta/pathology , Pregnancy , Real-Time Polymerase Chain Reaction , Receptors, Cytokine/genetics , Reproductive History , Young Adult
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