Journal: bioRxiv
Article Title: Mechanobiological Specialization of Choroid Plexus Macrophages Defined by Titin Expression
doi: 10.64898/2026.01.20.700716
Figure Lengend Snippet: Titin-expressing macrophages are present in the choroid plexus. (A) Heatmap of the top eight differentially expressed genes in each of the three ChP macrophage sub-clusters. Gene expression levels are represented on a normalized gradient scale. (B) DAB immunohistochemical stain of a 5 µm FFPE section of control ChP tissue using a CD163 antibody. CD163-positive macrophages are marked by brown staining, while cell nuclei are counterstained blue with hematoxylin, indicating their distribution within the vascularized ChP tissue. Scale bar = 40 µm. (C) Violin plots illustrating TTN expression levels in ChP samples from Alzheimer’s disease and control conditions. Each plot shows the distribution, density, and variability of TTN transcript counts in ChP macrophages within each condition. (D) Schematic representation of the experimental workflow for evaluation of TTN RNA enrichment in macrophages, involving tissue dissociation, CD163 positive cell enrichment, RNA isolation, cDNA synthesis, PCR amplification using isoform-specific TTN primers, and ΔΔCq calculation with GAPDH used for normalization. (E) Fold changes, computed from ΔΔCq, in TTN isoform expression relative to GAPDH in CD163-bead enriched macrophages relative to whole tissue. The x-axis represents different primer sets (1, 3, 7, and 12), and the y-axis shows fold changes (log scale). Each point represents a single donor sample/primer set pair. (F) Schematic representation of the TTN gene with highlighted primer binding sites, with genomic coordinates on chromosome 2, indicating selected splicing sites and isoforms of TTN. (G) Immunofluorescence images of ChP with anti-CD68 (red) and anti-titin (green) primary antibodies, co-stained with DAPI (blue), showing cytoplasmic titin protein in ChP macrophage cytoplasm. Merged images are in right column. Scale bars = 20 µm.
Article Snippet: RNA was extracted from CD163 microbead-separated macrophages (Miltenyi Biotec, Cat. #130-124-420) using the RNeasy Mini Kit (Qiagen), following the manufacturer’s protocol.
Techniques: Expressing, Gene Expression, Immunohistochemical staining, Staining, Control, Isolation, cDNA Synthesis, Amplification, Binding Assay, Immunofluorescence
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