Yazar "Erdal, Mehmet Emin" seçeneğine göre listele

Listeleniyor 1 - 6 / 6
  • Küçük Resim
    Öğe
    Apoptosis-related Fas and FasL gene polymorphisms' associations with knee osteoarthritis
    (Springer Heidelberg, 2013) Sezgin, Melek; Barlas, İbrahim Ömer; Yıldır, Seyfi; Türköz, Gözde; Ankaralı, Handan; Şahin, Günşah; Erdal, Mehmet Emin
    To investigate the associations between Fas and FasL gene polymorphisms and susceptibility to knee osteoarthritis. Genomic DNA was obtained from 146 patients with knee osteoarthritis and 102 healthy controls. Genotype distributions and allelic frequencies of four polymorphisms of Fas (-670 G > A rs1800682, -1377 G > A rs2234767) and FasL (IVS2nt-124 A > G rs5030772, -844 T > C rs763110) genes were compared between the groups. Thereafter, this association was investigated between patients and controls of the same sex. There were significant differences between patients with knee osteoarthritis and controls regarding the genotype distributions and allelic frequencies of Fas-1377 G > A polymorphism (P = 0.0001 and P = 0.005, respectively). The Fas-1377 GG genotype and G allele were significantly more frequent in patients with knee osteoarthritis than in controls. Genotype distributions and allelic frequencies of Fas-670 G > A, FasL-844 T > C, and FasL IVS2nt-124 A > G polymorphisms did not differ between the groups (P > 0.05). However, there were no significant differences between patients and controls of the same sex (P > 0.05). These findings suggest that the Fas-1377 G > A polymorphism in the Fas gene related with apoptosis may contribute to susceptibility to knee osteoarthritis in the Turkish population. There is a need for further studies to evaluate the role of apoptosis in large cohorts.
  • Küçük Resim
    Öğe
    Can Peripheral MicroRNA Expression Data Serve as Epigenomic (Upstream) Biomarkers of Alzheimer's Disease?
    (Mary Ann Liebert, Inc, 2016) Yılmaz, Şenay Görücü; Erdal, Mehmet Emin; Özge, Aynur Avcı; Sungur, Mehmet Ali
    Alzheimer's disease (AD) is a progressive neurodegenerative disorder and the most common form of dementia. However, biomarkers that require testing in the brain tissue pose a formidable practical barrier to AD diagnostic innovation. MicroRNAs (miRNAs) are responsible for control of gene expression at the posttranscriptional level and are essential for the function of neuronal networks and neuronal survival. miRNA expression can impact the regulation of APP (amyloid beta A4 precursor protein), PSEN1 (presenilin 1), PSEN2 (presenilin 2), and BACE1 (beta-secretase 1) genes in the brain that were previously implicated in AD pathophysiology. Little is known, however, on the extent to which peripheral tissue (e.g., whole blood) miRNA variation might offer clinical predictive value for AD. Moreover, few studies have examined multiple peripheral miRNA expression data at the same time. We report here, to the best of our knowledge, the first whole-blood-based and parallel study of seven miRNAs (hsa-miR-9-5p, hsa-miR-29a-3p, hsa-miR-106a-5p, hsa-miR-106b-5p, hsa-miR-107, hsa-miR-125a-3p, and hsa-miR-125b5p) in relation to AD susceptibility. Notably, these miRNAs are situated "upstream" to the genes implicated in AD. We measured the whole-blood miRNA expression by a real-time polymerase chain reaction in a large study sample (n = 281), comprising patients with AD (n = 172) and healthy controls (n = 109). A reduction in whole-blood expression of hsa-miR-9-5p, hsa-miR-106a-5p, hsa-miR-106b-5p, and hsa-miR-107 was significantly associated with an increased risk of AD (p < 0.05). Notably, after receiver operating characteristics curve analyses, hsa-miR-106a-5p displayed, as a predictor variable, 93% specificity and 68% sensitivity. On the other hand, the expression of hsa-miR29a-3p, hsa-miR-125a-3p, and hsa-miR-125b-5p was not significantly different between patients and controls (p > 0.05). In conclusion, these observations warrant replication in larger samples while making a contribution to translational research, precision medicine, and biomarker literatures, by expanding the current efforts for AD diagnostic innovation to the realm of epigenomic pathways such as miRNA expression variation among patients.
  • Küçük Resim
    Öğe
    Folate Metabolism Gene Polymorphisms and Risk for Down Syndrome Offspring in Turkish Women
    (Mary Ann Liebert, Inc, 2015) Ay, Özlem İzci; Ay, Mustafa Ertan; Erdal, Mehmet Emin; Çayan, Filiz; Tekin, Sevinç; Söylemez, Fatma; Yıldırım, Didem Derici
    Aims: Down syndrome (DS) is the most common chromosomal abnormality. Many studies have assessed the association between maternal gene polymorphisms involved in folate metabolism and the risk of having a DS offspring, but data are conflicting. Six common polymorphisms in folate-metabolizing genes were analayzed to determine possible risk factors for a child to be born having DS (DS mothers); these samples were taken from 47 Turkish mothers having DS children (case group) and 49 control mothers. Investigated polymorphisms include methylenetetrahydrofolate reductase (MTHFR) C677T (rs1801133), A1298C (rs1801131), methionine synthase reductase (MTRR) A66G (rs1801394), methylenetetrahydrofolate dehydrogenase (MTHFD1) G1958A (rs2236225), reduced folate carrier (RFC1) A80G (rs1051266), and cystathionine beta-synthase (CBS) 844ins68. Results: The frequency of the MTHFR 677C allele in DS mothers (79.8%) was significantly higher than in controls (66.3%), with a 0.499-fold increased risk of having a DS offspring (p=0.038 and 95% confidence interval [CI], 0.259-0.961). Mothers with the MTHFD1 1958A allele had a 1.880-fold increased risk of having a child with DS (p=0.031 and 95% CI, 1.060-3.335). No significant association was found for the other polymorphic variants in this study. Gene-gene interactions were not statistically significant. Conclusion: Polymorphic variants of the enzymes involved in folate metabolism may play an important role in determining the susceptibility of having a DS offspring. The gene-nutrition, gene-gene interactions and ethnicity are important variables to be considered in future studies.
  • Küçük Resim
    Öğe
    Regulating the Regulators in Attention-Deficit/Hyperactivity Disorder: A Genetic Association Study of microRNA Biogenesis Pathways
    (Mary Ann Liebert, Inc, 2017) Karakaş, Ümit; Ay, Özlem İzci; Ay, Mustafa Ertan; Wang, Wei; Sungur, Mehmet Ali; Çevik, Kenan; Erdal, Mehmet Emin
    Attention-deficit/ hyperactivity disorder (ADHD) is one of the most prevalent complex psychiatric disorders in children as well as adults. ADHD impacts not only the affected individuals but also their families and social and professional networks. The clinical and diagnostic criteria for ADHD remain imprecise, in part, due to lack of robust biomarkers. ADHD comprises multiple subsets of diseases that present a shared set of downstream clinical findings, while displaying extensive molecular heterogeneity. This calls for innovation in diagnostic strategies that can help establish an ADHD diagnosis unequivocally as well as guiding precision medicine in this common mental health disorder. No study has examined, to the best of our knowledge, the upstream regulation of miRNAs that impact the downstream final ADHD phenotype. The latter focus on putative genetic biomarkers that regulate the regulators and can be tested empirically, for example, through genetic association analyses of the biogenesis pathways for miRNAs that impact the ADHD phenotype. Hence, we report here polymorphic variation in 10 miRNA biogenesis pathway candidate genes, including RNASEN, DGCR8, XPO5, RAN, DICER1, TARBP2, AGO1, AGO2, GEMIN3, and GEMIN4, in a large sample from the Eastern Mediterranean region (N= 355; 191 cases and 164 controls). We found that AGO1 rs595961 was significantly associated with ADHD susceptibility (p < 0.05). While polymorphic variation in other miRNA biogenesis pathway genes did not display a significant association in the present sample, the observations reported herein on miRNA biogenesis variation offer a new avenue of research for innovation in biomarker discovery concerning ADHD and other complex psychiatric diseases with major global health burden.
  • Küçük Resim
    Öğe
    Relation of the Fas and FasL gene polymorphisms with susceptibility to and severity of rheumatoid arthritis
    (Springer Heidelberg, 2013) Yıldır, Seyfi; Sezgin, Melek; Barlas, İbrahim Ömer; Türköz, Gözde; Ankaralı, Handan; Şahin, Günşah; Erdal, Mehmet Emin
    To investigate associations of the Fas and FasL genes polymorphisms with rheumatoid arthritis (RA). One hundred patients with RA and age-, sex- and ethnically matched 101 controls were included. Four polymorphisms of Fas (-670 A > G rs1800682, -1377 G > A rs2234767) and FasL (IVS2nt-124 A > G rs5030772, -844 T > C rs763110) genes were typed from genomic DNA. Genotype distributions and allelic frequencies were compared between patients and control subjects. After the history and clinical examination of patients with RA, in terms of pain, fatigue and general health status were evaluated by visual analogue scale. Thereafter, erythrocyte sedimentation rate, C-reactive protein, blood count and rheumatoid factor levels were measured. The Disease Activity Score-28, Health Assessment Questionnaire and modified Sharp score were used to evaluate the disease activity, functional disability and radiological damage, and their relationships with the Fas and FasL gene polymorphisms were investigated. In patients with RA, CT and TT genotypes of FasL-844, polymorphism were twofold and 4.8-fold higher, and AA genotype of FasL IVS2nt-124 polymorphism was 3.4-fold higher than the control group (respectively, p = 0.05, p = 0.002, p = 0.039). T allele of FasL-844 polymorphism was more frequent in patients than controls (respectively, 52.5 vs. 41.4 %, p = 0.027). Any association was not detected between Fas (-670 A > G, -1377 G > A) and FasL (-844 T > C, IVS2nt-124 A > G) gene polymorphisms with the disease activity scores, functional disability and radiological damage. However, the Fas-670 A > G polymorphism was associated with drug therapy (p = 0.049). The distribution of GG genotype was higher compared to GA or AA genotypes in patients using triple disease-modifying antirheumatic drug therapy (71.4, 14.3 and 14.3 %, respectively). These findings suggest that the -844 T > C and IVS2nt-124 A > G polymorphisms in the FasL gene related with apoptosis may increase genetic susceptibility to RA in a Turkish population. In addition, the Fas-670 A > G gene polymorphism may be associated with disease progression. There is a need for further studies to clarify the genetic role of apoptosis in RA.
  • Küçük Resim
    Öğe
    SNP Variation in MicroRNA Biogenesis Pathway Genes as a New Innovation Strategy for Alzheimer Disease Diagnostics: A Study of 10 Candidate Genes in an Understudied Population From the Eastern Mediterranean
    (Lippincott Williams & Wilkins, 2016) Yılmaz, Şenay Görücü; Erdal, Mehmet Emin; Özge, Aynur Avcı; Sungur, Mehmet Ali
    Alzheimer disease (AD) is a common complex neurodegenerative disorder accounting for nearly 50% to 70% of dementias worldwide. Yet the current diagnostic options for AD are limited. New diagnostic innovation strategies focusing on novel molecules and pathways are sorely needed. In this connection, microRNAs (miRNAs) are conserved small noncoding RNAs that regulate posttranscriptional gene expression and are vital for neuronal development and its functional sustainability. Conceivably, biological pathways responsible for the biogenesis of miRNAs represent a veritable set of upstream candidate genes that can be potentially associated with the AD pathophysiology. Notably, whereas functional single-nucleotide polymorphisms (SNPs) in miRNA biogenesis pathway genes have been studied in other complex diseases, surprisingly, virtually no such study has been conducted on their relevance in AD. Moreover, novel diagnostics identified in easily accessible peripheral tissues such as the whole blood samples represent the initial entry or gateway points on the biomarker discovery critical path for AD. To the best of our knowledge, we report here the first association study of functional SNPs, as measured by real-time PCR in 10 upstream candidate genes critically situated on the miRNA biogenesis pathway, in a large sample of AD patients (N=172) and healthy controls (N=109) in a hitherto understudied world population from the Mersin region of the Eastern Mediterranean. We observed a significant association between 2 candidate genes and AD, TARBP2 rs784567 genotype and AD ((2)=6.292, P=0.043), and a trend for RNASEN rs10719 genotype ((2)=4.528, P=0.104) and allele (P=0.035). Functional SNP variations in the other 8 candidate genes (DGCR8, XPO5, RAN, DICER1, AGO1, AGO2, GEMIN3, and GEMIN4) did not associate with AD in our sample. Given the putative biological importance of miRNA biogenesis pathways, these emerging data can provide a new foundation to stimulate future debate and genetic investigations of AD, focusing on new molecular mechanisms such as miRNA biogenesis, particularly in accessible peripheral tissues for novel molecular diagnostics for dementia.