Atilla, Pergin

Background: Primary ciliary dyskinesia (PCD) is a rare genetic disorder characterized by recurrent sinopulmonary infections due to motile cilia defects. The disease is genetically heterogeneous, with abnormalities in structural ciliary proteins. Zinc finger MYND-type containing 10 (ZMYND10) is essential for the assembly of outer dynein arms (ODA), with chaperones like Glucose-regulated protein 78 (GRP78) facilitating protein folding. This study investigates ZMYND10 and Dynein axonemal heavy chain 5 (DNAH5) mutations in individuals with PCD. Methods: Eight individuals aged 14–22 with clinical PCD symptoms and confirmed DNAH5 mutations were included. We analyzed the correlation between DNAH5 abnormalities and preassembly/chaperone proteins using immunofluorescence labeling. Nasal swabs were double-labeled (DNAH5–β-tubulin, β-tubulin–ZMYND10, β-tubulin–GRP78) and examined via fluorescence microscopy. Serum metabolomics and proteomics were also assessed. Results: The corrected total cell fluorescence (CTCF) levels of DNAH5, ZMYND10, and GRP78 were significantly different between PCD individuals and controls. Metabolomic analysis showed reduced valine, leucine, and isoleucine biosynthesis, with increased malate and triacylglycerol biosynthesis, malate-aspartate and glycerol phosphate shuttles, and arginine/proline metabolism, suggesting mitochondrial and ER stress. Conclusions: The altered expression of DNAH5, ZMYND10, and GRP78, along with metabolic shifts, points to a complex link between ciliary dysfunction and cellular stress in PCD. Further studies are needed to clarify the underlying mechanisms.

Background/Objectives: Primary ciliary dyskinesia (PCD) (OMIM: 244400) is a hereditary, rare disorder with a high prevalence in Turkey due to a high rate of consanguinity. The disorder is caused by malfunctioning motile cilia and is characterized by a variety of clinical symptoms including sinusitis, otitis media and chronic obstructive pulmonary disease. This study presents the first assessment of the efficacy of immunofluorescence (IF) labeling for diagnosing PCD in Turkey by correlating IF with clinical observations when genetic data are scarce. Methods: We have a cohort of 54 PCD-suspected individuals with an age range of 5–27 years classified into two groups: group A with available genomic data (8 individuals) and group B with no available genomic data (46 individuals). We performed immunofluorescence analysis to confirm the pathogenicity of the variants in individuals with a prior genetic diagnosis and to confirm a PCD diagnosis in individuals with typical PCD symptoms and no genetic diagnosis. Results: All individuals had airway infections and displayed clinical symptoms of PCD. Our data revealed an absence of outer dynein arm dynein heavy chain DNAH5 in individuals with pathogenic variants in DNAH5 and DNAAF1 and in 17 other PCD-suspected individuals, an absence of nexin–dynein regulatory complex component GAS8 in 8 PCD-suspected individuals, an absence of outer dynein arm dynein heavy chain DNAH11 in 6 PCD-suspected individuals and an absence of radial spoke head component RSPH9 in 2 PCD-suspected individuals. Furthermore, the pathogenicity of ARMC4 variants was confirmed by the absence of the outer dynein arm docking complex component ARMC4 and the proximal localization of DNAH5. Conclusions: Immunofluorescence analysis, owing to its lower cost and quicker turnaround time, proves to be a powerful tool for diagnosing PCD even in the absence of genetic data or electron microscopy results.

AbstractParkinson's disease (PD) is a complex, multifactorial neurodegenerative disease with a prevalence of 1% over the age of 55. Neuropathological hallmarks of PD include the loss of dopaminergic neurons in the substantia nigra pars compacta and the accumulation of Lewy bodies that contain a variety of proteins and lipids including alpha‐synuclein (α‐syn). Although the formation of α‐syn occurs intracellularly, it can also be found in the extracellular space where it can be taken up by neighboring cells. Toll‐like receptor 2 (TLR2) is an immune system receptor that has been shown to recognize extracellular α‐syn and modulate its uptake by other cells. Lymphocyte‐activation gene 3 (LAG3), an immune checkpoint receptor, has also been proposed to play a role in extracellular α‐syn internalization; however, a recent study has disputed this role. Internalized α‐syn can trigger expression and secretion of inflammatory cytokines such as tumor necrosis factor alpha (TNF‐α), interleukin (IL)‐1β, IL‐2, and IL‐6 and induce neuroinflammation, apoptosis, and mitophagy that results in cellular death. In this study, we tested if N‐acetylcysteine (NAC), an anti‐inflammatory and anti‐carcinogenic drug, can circumvent the detrimental effects of neuroinflammation and induce an anti‐inflammatory response by modulating transcription and expression of TLR2 and LAG3 receptors. Cells overexpressing wild‐type α‐syn were treated with TNF‐α to induce inflammation followed by NAC to inhibit the deleterious effects of TNF‐α‐induced inflammation and apoptosis. SNCA gene transcription and α‐syn protein expression were validated by q‐PCR and Western blot (WB), respectively. Cell viability was measured, and apoptosis was evaluated by WB and terminal deoxynucleotidyl transferase nick end labeling methods. Alterations in LAG3 and TLR2 receptor levels were evaluated by immunofluorescent labeling, WB, and q‐PCR. TNF‐α not only increased inflammation but also increased endogenous and overexpressed α‐syn levels. NAC treatment decreased expression of TLR2 and increased transcription of LAG3 receptor and diminished inflammation‐mediated toxicity and cell death. Here, we demonstrate that NAC can reduce neuroinflammation that occurs as a result of alpha‐synuclein overexpression, via a TLR2‐associated pathway, making it a promising candidate for therapeutic intervention. Further studies are needed to elucidate molecular mechanisms and pathways related to neuroinflammation in PD and to develop possible new therapeutic approaches to slow the clinical progression of PD.