👤 Zübeyde Çakır

BackgroundEpigenetic dysregulation is increasingly recognized as a key mechanism in the development and progression of Alzheimer's disease (AD). Herpes simplex virus type 1 (HSV-1) infection has been proposed as a potential biological trigger that may accelerate neurodegeneration through epigenetic modifications. Among HSV-1 structural proteins, glycoprotein B (HSV-gB) may influence host-virus interactions affecting neuronal gene regulation.ObjectiveThis study aimed to investigate the contribution of HSV-gB to AD-related epigenetic alterations and to determine whether HSV-gB exposure exacerbates epigenetic dysregulation in two in vitro neuronal AD models.MethodsHuman SH-SY5Y neuroblastoma cells were used to establish two AD models: a differentiation-based aging model induced by retinoic acid and brain-derived neurotrophic factor (RA + BDNF), and an amyloid aggregation model induced by amyloid-β 1-42 (Aβ Show less

Asymptomatic Alzheimer's Disease (AsymAD) is a preclinical stage of Alzheimer's Disease (AD) identified by amyloid plaques and neurofibrillary tangles in cognitively normal individuals and offers essential understanding for early diagnosis and treatment of AD. To uncover molecular insights into AsymAD, RNA sequencing (RNA-seq) datasets from two different consortia, ROSMAP (Religious Orders Study and Memory and Aging Project) and MSBB (Mount Sinai Brain Bank), were investigated. The individuals in the datasets were grouped into AD and AsymAD based on clinical and neuropathological criteria. Differentially expressed genes (DEGs), differentially expressed transcripts (DETs), and differentially used transcripts (DUTs) were identified between AD and AsymAD samples. The results were interpreted through functional enrichment analysis and compared with the predefined lists of AD-related and learning-memory-cognition-related genes, and genes from an independent mouse dataset. The genes from the list of DEGs, DETs and DUTs were mapped onto a human protein-protein interaction network, revealing subnetworks associated with AsymAD. This led to the discovery of biomarker candidate genes: NRXN3, DGKB, ADAMTS2, GNG4, ENPP5, PCOLCE, COL25A1, COL26A1, MRPL1, and MRPL30. This study introduces an innovative approach by including DETs and DUTs in the analyses, beyond the standard focus on DEGs, pointing out comprehensive insights into the molecular mechanisms of AsymAD. In addition, combining the results of the subnetwork analysis from DEGs, DETs, and DUTs provided a new perspective to AsymAD and resulted in the discovery of further important genes, which can pave the way for early detection and intervention of AD. Show less

Genetic polymorphisms play a crucial role in regulating the physiological mechanisms underlying athletic performance, including muscle structure, energy metabolism, and cognitive functions. In recent years, increasing attention has been directed toward genetic variants that may influence cognitive traits such as motivation, stress tolerance, and attention, which are critical for optimal athletic performance. The present study aimed to provide the first preliminary meta-analysis of the association between athlete status and specific candidate polymorphisms related to cognitive processes (COMT rs4680, BDNF rs6265, OPRM1 rs1799971, and APOE rs7412/rs429358). A total of 17 case-control studies meeting the inclusion criteria were retrieved from relevant databases and included in the analysis. Statistical evaluations were performed using random- and fixed-effects models with a 95% confidence interval. The results indicated a potential association between the COMT Val158Met polymorphism and athlete status in both the overall and power athlete subgroups (p < 0.05). In contrast, no significant associations were observed for BDNF rs6265, OPRM1 rs1799971, or APOE rs7412/rs429358. However, this finding is based on a small number of studies and must be interpreted as exploratory. While this preliminary meta-analysis highlights a significant evidence gap, it also underscores, due to methodological limitations, the need for further empirical studies to understand the potential role of these polymorphisms in athlete status. Show less

The adipose tissue-derived hormone leptin can drive decreases in food intake while increasing energy expenditure. In diet-induced obesity, circulating leptin levels rise proportionally to adiposity. Despite this hyperleptinemia, rodents and humans with obesity maintain increased adiposity and are resistant to leptin's actions. Here we show that inhibitors of the cytosolic enzyme histone deacetylase 6 (HDAC6) act as potent leptin sensitizers and anti-obesity agents in diet-induced obese mice. Specifically, HDAC6 inhibitors, such as tubastatin A, reduce food intake, fat mass, hepatic steatosis and improve systemic glucose homeostasis in an HDAC6-dependent manner. Mechanistically, peripheral, but not central, inhibition of HDAC6 confers central leptin sensitivity. Additionally, the anti-obesity effect of tubastatin A is attenuated in animals with a defective central leptin-melanocortin circuitry, including db/db and MC4R knockout mice. Our results suggest the existence of an HDAC6-regulated adipokine that serves as a leptin-sensitizing agent and reveals HDAC6 as a potential target for the treatment of obesity. Show less