Birsen Can Demirdöğen

Objectives: The neutrophil-to-lymphocyte ratio (NLR) is an easily obtainable blood-based marker reflecting systemic inflammation and immune activation. Its temporal behavior during relapses, corticosteroid treatment, and recovery in relapsing-remitting multiple sclerosis (RRMS) remains unclear. The objective of this study was to evaluate longitudinal changes in NLR and disability measured by Expanded Disability Status Scale (EDSS) across relapses, end of corticosteroid therapy, and one-month follow-up in RRMS. Methods: A total of 20 patients with RRMS relapses and 60 healthy controls were included in our study. Blood samples were collected once from controls and three times from patients: before corticosteroid therapy (BT), at the end of treatment (ET), and one month after therapy (1 M). NLR was calculated from automated complete blood counts. EDSS was scored by a trained neurologist at each visit. Statistical analyses were performed using SPSS. Correlation between NLR and EDSS was evaluated using repeated-measures correlation (rmcorr) in RStudio. Results: NLR was significantly higher in BT vs. controls (p=0.009) and increased further at ET (p<0.001), followed by a decline at 1 M (p=0.034). EDSS scores decreased significantly at ET and remained lower at 1 M. Receiver Operating Characteristic (ROC) analysis showed moderate discrimination for BT vs. control groups (AUC=0.696, p=0.009) and ET vs. BT (AUC=0.727, p=0.014), while 1 M vs. ET was not significant (AUC=0.626, p=0.172). Conclusions: NLR dynamically reflects both inflammatory activity and corticosteroid-induced immune modulation in RRMS. Although its diagnostic power is modest, NLR is a practical, cost-effective biomarker that may complement clinical and radiological tools in monitoring relapse and treatment response.

Objectives: The aim was to evaluate the effect of type 2 diabetes mellitus on the root canal microbiota and its response to antimicrobial photodynamic therapy (aPDT) combined with chemomechanical preparation in asymptomatic apical periodontitis (AP), by next-generation sequencing. Materials and methods: A total of 22 teeth with a single root and single canal, diagnosed with asymptomatic AP, were included in this study: 11 teeth from patients with T2D (T2D group) and 11 from systemically healthy individuals (Control group). Root canal samples were collected before root canal treatment and after aPDT combined with chemomechanical preparation. Following chemomechanical preparation, canals were incubated with methylene blue for 5 min and photoactivated with a 630 nm LED for 60 s. Root canal samples were collected at two time points—before treatment (Control.Pre, T2D.Pre) and after treatment (Control.aPDT, T2D.aPDT). Following propidium monoazide (PMA) treatment, genomic DNA was isolated using a silica column method and quantified fluorometrically. The V3–V4 regions of the 16S rRNA gene were amplified and sequenced using the Illumina MiSeq platform. Data were processed in QIIME2 with DADA2 for denoising and classified taxonomically using Human Oral Microbiome Database (HOMD). Diversity analyses and statistical evaluations (PERMANOVA and multivariable association analysis using MaAsLin3; FDR-corrected) were performed in R. Results: A total of 44 root canal samples (Control.Pre, Control.aPDT, T2D.Pre, T2D.aPDT; n = 11) were analyzed via 16S rRNA V3–V4 sequencing, yielding 4.6 million high-quality reads and 2,745 Amplicon Sequence Variants (ASVs). Alpha diversity did not differ between pre and post disinfection procedure samples in healthy individuals ( p > 0.05), whereas a significant reduction in observed ASV richness was detected in the T2D group after the disinfection procedures ( p < 0.05). The number of ASVs shared between pre and post disinfection procedure samples was lower in the T2D group than in controls. Beta diversity based on unweighted UniFrac distances showed significant shifts after the disinfection procedures in both groups ( p < 0.05), while weighted UniFrac analyses showed no significant differences ( p > 0.05). Taxonomic analysis revealed a post disinfection increase in oxygen tolerant taxa and a reduction in obligate anaerobes in both groups, with more pronounced changes in the T2D group. Conclusions: Following chemomechanical preparation and aPDT, a pronounced restructuring of the root canal microbiota was observed in both healthy individuals and individuals with T2D. In individuals with T2D, the post-disinfection period was characterized by reduced alpha diversity and a lower number of shared ASVs, indicating more limited microbial continuity. Clinical relevance: The reduced microbial stability observed in individuals with diabetes suggests that systemic metabolic status may affect microbial responses to chemomechanical disinfection combined with aPDT.

Multiple sclerosis (MS) is a chronic inflammatory disease in which immune cells attack the central nervous system (CNS) and cause degeneration of the myelin sheath. Although disease-modifying therapies are commonly used in the treatment of MS, these therapies cannot fully prevent or reverse the course of neurological deterioration. Furthermore, the response of patients with MS to these drugs may vary from person to person and over time. Therefore, the demand for new and more effective treatments continues. MicroRNAs (miRNAs) have the potential to alter biological processes that lead to various diseases. Hence, dysregulated miRNA levels are thought to be associated with the pathogenesis of MS. Considering the regulatory role of miRNAs in both the CNS and immune response, many studies have proposed them as potential new therapeutic targets for MS in addition to being potential biomarkers. In this traditional review, the primary focus is on miRNA-based therapeutic approaches, followed by a compilation of studies that utilized miRNA therapy to inhibit upregulated miRNAs in the animal model of MS, known as Experimental Autoimmune Encephalomyelitis (EAE).

Multiple sclerosis (MS) is an autoimmune neurodegenerative disorder, with relapsing–remitting MS (RRMS) being the most common subtype. Interferon-γ (IFN-γ) plays a dual role in MS pathogenesis. MicroRNAs (miRNAs) have emerged as potential diagnostic biomarkers. This study examined the effect of relative expression of hsa-miR-24-3p and hsa-miR-181d-3p, plasma IFN-γ levels, and the IFNG rs2069727 T/C variant on MS risk, evaluating their interrelationships and diagnostic potential. This case–control study comprised two overlapping groups—a genetic polymorphism group (330 RRMS, 330 healthy controls (HCs)) and a miRNA group (25 glatiramer acetate (GA)-treated RRMS patients, 25 treatment-naïve RRMS patients, and 25 HCs)- collected at the Ankara Bilkent City Hospital Neurology Polyclinic. The IFNG rs2069727 T/C variant did not display a statistically significant disparity between RRMS patients and HCs. Significantly elevated hsa-miR-24-3p and hsa-miR-181d-3p relative expression levels were observed in GA-treated and treatment-naïve RRMS patients compared to HCs. Conversely, age-adjusted plasma IFN-γ concentrations were markedly lower in GA-treated and treatment-naïve RRMS patients versus HCs. Individuals with low plasma IFN-γ levels (≤ 1.311 pg/mL) demonstrated significantly elevated hsa-miR-24-3p relative expression compared to the high IFN-γ group (> 1.311 pg/mL). Conversely, subjects with low hsa-miR-181d-3p levels (≤ 2.90) exhibited significantly higher plasma IFN-γ concentrations relative to those with high hsa-miR-181d-3p levels (> 2.90). In the GA-treated group, EDSS negatively correlated with age-adjusted plasma IFN-γ. This study identified age-adjusted plasma IFN-γ, hsa-miR-24-3p, and hsa-miR-181d-3p expression as potential blood-based biomarkers for RRMS diagnosis and analyzed them alongside disability scores. The miRNAs in this study can be further evaluated as prospective therapeutic targets.

Multiple sclerosis (MS) is a chronic, demyelinating disorder of the central nervous system that is widely accepted to result from a complex interplay of genetic and environmental factors. The involvement of clusterin in neurodegenerative and autoimmune diseases has been highlighted, but its role in MS remains unclear. This study aimed to investigate the association of four single nucleotide polymorphisms (SNPs) in the clusterin gene (CLU) with MS susceptibility. The study group consisted of 310 patients with RRMS (pwRRMS) and 310 controls. 25 treatment-naïve pwRRMS, 25 pwRRMS on fingolimod treatment and 25 controls composed a subgroup for further analysis. The genotypes of 4 CLU SNPs were determined using either restriction endonuclease digestion following PCR (rs11136000 & rs3087554) or the real-time PCR method using TaqMan genotyping assays (rs2279590 & rs1532278). Plasma clusterin concentration was determined by ELISA in the subgroup (n = 75). Our results revealed that CLU rs3087554 C allele (p = .008) and TC + CC genotype were significantly associated with RRMS (p = .002). Furthermore, haplotype analysis has also shown that T-C-T-T haplotype was associated with RRMS (p < .001). Moreover, plasma clusterin concentrations were significantly higher in pwRRMS on fingolimod therapy compared to treatment-naïve pwRRMS and the control group. In addition, plasma clusterin concentration was increased in patients with rs11136000 & rs1532278 CC genotypes in the subgroup. These findings suggest that CLU SNPs and plasma clusterin concentrations could serve as significant biomarkers at different stages of MS.

To uncover molecular changes underlying blood-brain-barrier dysfunction in Alzheimer’s disease, we performed single nucleus RNA sequencing in 24 Alzheimer’s disease and control brains and focused on vascular and astrocyte clusters as main cell types of blood-brain-barrier gliovascular-unit. The majority of the vascular transcriptional changes were in pericytes. Of the vascular molecular targets predicted to interact with astrocytic ligands, SMAD3, upregulated in Alzheimer’s disease pericytes, has the highest number of ligands including VEGFA, downregulated in Alzheimer’s disease astrocytes. We validated these findings with external datasets comprising 4,730 pericyte and 150,664 astrocyte nuclei. Blood SMAD3 levels are associated with Alzheimer’s disease-related neuroimaging outcomes. We determined inverse relationships between pericytic SMAD3 and astrocytic VEGFA in human iPSC and zebrafish models. Here, we detect vast transcriptome changes in Alzheimer’s disease at the gliovascular-unit, prioritize perturbed pericytic SMAD3-astrocytic VEGFA interactions, and validate these in cross-species models to provide a molecular mechanism of blood-brain-barrier disintegrity in Alzheimer’s disease.

Purpose The etiology and pathogenesis of pseudoexfoliation syndrome (PEX) and its advancement into pseudoexfoliative glaucoma (PEG) are not fully understood. In this study, we aimed to evaluate the possible role played by two circulating microRNAs (miR-146a-5p and miR-196a-5p) in plasma and their functional genetic variants MIR146A rs2910164 and MIR196A2 rs11614913 in susceptibility to PEG or PEX. Methods Plasma miRNA relative expression of 27 patients with PEG, 25 patients with PEX and 27 controls was determined using quantitative RT-PCR, and fold change was calculated using the 2^−ΔΔCt method. Genotyping of 300 patients with PEG, 300 patients with PEX, and 300 controls was performed using a PCR-restriction fragment length polymorphism analysis. Result Plasma miR-146a-5p relative expression was significantly elevated in patients with PEG (3.9-fold) (P < .000) and patients with PEX (2.7-fold) relative to controls (P = .001). The diagnostic ability of plasma miR-146a-5p expression fold change was good for discriminating PEG vs. controls (AUC = 0.897, P < .000), and the optimal decision threshold was 1.83 (sensitivity = 74%, specificity = 93%). Plasma miR-196a-5p relative expression did not differ significantly between study groups. No significant difference in terms of the minor allele frequency or the distribution of genotypes for MIR146A rs2910164 G/C or MIR196A2 rs11614913 C/T was observed between study groups. Conclusions Circulating miR-146a-5p can contribute to the risk of PEX/PEG. Therefore, we propose that plasma miR-146a-5p can be developed as a potential biomarker for the minimally invasive diagnoses of PEX/PEG and as a potential therapeutic target with further studies.

Purpose: Pseudoexfoliation syndrome (PEX) is distinguished by the deposition of fibrillary material within the aqueous humor and, in most cases, causes pseudoexfoliative glaucoma (PEG). The pathophysiologies of PEX and PEG are not completely explained. Therefore, this study aimed to assess the potential relationship between single nucleotide polymorphisms (SNPs) in the 3ʹ untranslated region or introns of the clusterin gene (CLU) and the susceptibility to developing PEG or PEX. Methods: Two hundred and forty patients with PEX, 239 patients with PEG, and 240 control subjects were included. Genotyping was carried out using real-time PCR (rs2279590 C/T and rs1532278 C/T) or PCR followed by restriction endonuclease digestion (rs11136000 C/T and rs3087554 T/C). Results: The minor alleles or genotypes of CLU SNPs were not significantly associated with PEX or PEG. IOP values of patients with PEX carrying the homozygote polymorphic TT genotype were significantly elevated compared with PEX cases with the CT or CC genotypes for rs2279590, rs11136000 and rs1532278 (P = .009, P = .007, P = .010, respectively). Conclusion: We present the first evidence that three SNPs in CLU gene (rs2279590, rs11136000 and rs1532278) might induce a rise in IOP in patients with PEX, conferring susceptibility to develop PEG.

This study aimed to assess the possible association between cognitive impairment and two important biochemical biomarkers of oxidative stress, thiol‐disulfide homeostasis (TDH), and ischemia‐modified albumin (IMA) in patients with multiple sclerosis (MS). This study included 85 patients with MS (38 treatment‐naïve relapsing–remitting MS (RRMS), 31 RRMS on fingolimod therapy, and 16 secondary progressive MS (SPMS)) and 33 healthy controls. Cognitive evaluation was carried out by applying the Brief International Cognitive Assessment for Multiple Sclerosis (BICAMS) test battery and the scores were adjusted for age and years of education. Plasma TDH was assessed using an automated method and plasma IMA levels were determined using the cobalt‐albumin binding assay. Plasma native thiol and total thiol levels were significantly decreased in patients with SPMS when compared with the naïve patients and healthy controls. Cognitive impairment was detected in 47.4% of naïve patients, 64.5% of patients on fingolimod therapy, and 80% of patients with SPMS. Naïve patients or patients on fingolimod therapy who were cognitively impaired had significantly decreased levels of native thiol and total thiol compared to the cognitively normal patients. Logistic regression analysis revealed total thiol and native thiol to be significantly associated with cognitive impairment in naïve patients and patients on fingolimod therapy. Significant correlations were determined between BICAMS scores, TDH, IMA, clinical indices of disease severity (EDSS and MSSS), and magnetic resonance imaging parameters. This study has shown for the first time that plasma TDH parameters are associated with cognitive impairment in MS.