👤 Hamit Çelik

Mitochondrial dysfunction, oxidative stress, and neuroinflammation play a critical role in the occurrence and progression of Alzheimer's disease (AD). MicroRNAs (miRNAs) have been studied recently as potential therapeutic approaches for AD. In this study, we examined the function and underlying mechanism of microRNA-25802 (miR-25802), a newly discovered miRNA in an AD model. In order to evaluate the levels of oxidative stress, mitochondrial damage and neuroinflammation in neuroblastoma cells, four experimental groups were created: control group (neuroblastoma cells, SH-SY5Y), amyloid beta (Aβ)-induced neuroblastoma cells (SY5Y-Aβ), small extracellular vesicles (sEVs)-only group and miR-25802-loaded small extracellular vesicles (sEV-miR25802) administered group. Neuroinflammation, oxidative stress, mitochondrial damage, tau hyperphosphorylation, and Aβ accumulation were evaluated in Aβ-induced neuroblastoma cells. Oxidative stress was analyzed by measuring reactive oxygen species (ROS), malondialdehyde (MDA), lactate dehydrogenase (LDH), superoxide dismutase (SOD), and glutathione peroxidase 1 (GPX1). Inflammatory markers such as tumor necrosis factor-alpha (TNF-α), intercellular adhesion molecule 1 (ICAM1), and brain-derived neurotrophic factor (BDNF) mRNA levels, a neurotrophic factor, were evaluated by RT-qPCR. Neurofilament light chain (NfL), vascular endothelial growth factor-A (VEGF-A), macrophage migration inhibitory factor (MIF), monocyte chemoattractant protein-1 (MCP-1) and cytochrome c (Cyt-c), mitochondrial transcription factor A (TFAM), PTEN-induced kinase 1 (PINK1) and dynamin-1-like protein (DNM1L) protein levels were determined by ELISA. Mechanistically, sEV-miR25802 were shown to provide anti-inflammatory and neuroprotective effects by regulating neuroinflammation, mitochondrial dysfunction, and oxidative stress. These findings reveal the regulatory role of miR-25802 on neuroinflammation, mitochondrial damage, and oxidative stress and suggest that it may be a potential therapeutic target for AD. Show less

In this study, we investigated the therapeutic potential of miR-206-3p delivered via small extracellular vesicles (sEVs) in an in vitro Alzheimer's disease model using SH-SY5Y human neuroblastoma cells treated with amyloid beta (Aβ). The sEV-miR-206-3p complexes were successfully loaded with miR-206-3p (∼0.001 copies per particle) without disrupting vesicle integrity or inducing cytotoxicity at the optimized concentration of 5 μg/mL. Aβ treatment significantly increased oxidative stress markers (ROS, MDA, LDH) and decreased antioxidant enzyme activity (SOD), while GPX1 showed an opposite trend. Furthermore, Aβ elevated proinflammatory gene expression (ICAM1, TNF-α) and reduced neuroprotective BDNF levels, induced mitochondrial dysfunction (increased Cyt-c, PINK1, DNM1L; decreased TFAM), impaired synaptic proteins (CPLX2, ROR1), and promoted tau phosphorylation and Aβ accumulation. Treatment with sEV-miR-206-3p effectively mitigated these alterations, reducing oxidative stress, suppressing neuroinflammatory responses, restoring mitochondrial function and synaptic protein levels, and attenuating tau and Aβ pathology. These findings demonstrate that miR-206-3p-loaded sEVs protect neuroblastoma cells from Aβ-induced neurodegenerative processes, highlighting their potential as a novel drug delivery system for neuroprotection. Show less

Familial hypercholesterolemia (FH) is an inherited metabolic disorder that increases cardiovascular risk from childhood. Despite its frequency, pediatric diagnosis and treatment remain limited, particularly in developing countries. Retrospective analysis of pediatric patients with genetically confirmed heterozygous FH (HeFH). Genetic testing included sequencing of the genes Among the cohort of 124 patients only 28.2% of patients were diagnosed via routine lipid screening, though 90.3% had a positive family history. After diagnosis, 16.1% declined treatment and 41.1% were lost to follow-up. Most genetic diagnoses involved pathogenic This is the first large pediatric HeFH cohort study from Türkiye and provides data on both genetic background and treatment outcome. Despite genetic confirmation, significant gaps remain in early diagnosis, treatment acceptance, and long-term follow-up. Both atorvastatin and pitavastatin proved to be safe and effective. These results suggest a need for national screening programmes, family education, dietary counselling, and consistent follow-up. 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

Hypertrophic cardiomyopathy is a common genetic heart disease and up to 40%-60% of patients have mutations in cardiac sarcomere protein genes. This genetic diagnosis study aimed to detect pathogenic or likely pathogenic sarcomeric and non-sarcomeric gene mutations and to confirm a final molecular diagnosis in patients diagnosed with hypertrophic cardiomyopathy. A total of 392 patients with hypertrophic cardiomyopathy were included in this nationwide multicenter study conducted at 23 centers across Türkiye. All samples were analyzed with a 17-gene hypertrophic cardiomyopathy panel using next-generation sequencing technology. The gene panel includes ACTC1, DES, FLNC, GLA, LAMP2, MYBPC3, MYH7, MYL2, MYL3, PLN, PRKAG2, PTPN11, TNNC1, TNNI3, TNNT2, TPM1, and TTR genes. The next-generation sequencing panel identified positive genetic variants (variants of unknown significance, likely pathogenic or pathogenic) in 12 genes for 121 of 392 samples, including sarcomeric gene mutations in 30.4% (119/392) of samples tested, galactosidase alpha variants in 0.5% (2/392) of samples and TTR variant in 0.025% (1/392). The likely pathogenic or pathogenic variants identified in 69 (57.0%) of 121 positive samples yielded a confirmed molecular diagnosis. The diagnostic yield was 17.1% (15.8% for hypertrophic cardiomyopathy variants) for hypertrophic cardiomyopathy and hypertrophic cardiomyopathy phenocopies and 0.5% for Fabry disease. Our study showed that the distribution of genetic mutations, the prevalence of Fabry disease, and TTR amyloidosis in the Turkish population diagnosed with hypertrophic cardiomyopathy were similar to the other populations, but the percentage of sarcomeric gene mutations was slightly lower. Show less