Fig. 5

Pathological truncated tau protein induced lipid changes and LD formation in brain resident immune cells. A-B Expression of endogenous and truncated tau protein by human SH-SY5Y neuroblastoma cells. C-D Quantification showed that the expression of endogenous tau was not changed in time, however, truncated tau increased (mean ± SD). E-F Analysis of cultivation media demonstrated higher secretion of the proline-rich domain of tau compared to total tau (boxplots with min to max, student’s t-test with p-value). G Cytotoxicity measured by AlamarBlue assay and displayed as boxplots (student’s t-test with p-value). H Principal component analysis (PCA), and orthogonal partial least square discriminant analysis (OPLS-DA). I Metabolic map showing results from significance testing for lipids – student’s t-test (p-value and fold change). J Lipid ontology enrichment analysis. K-L Primary rat microglia were co-cultivated with neuroblastoma cells expressing truncated tau. Representative images of DAPI (blue), BODIPY+ (green), and IBA-1 (red) staining in microglia and quantification of BODIPY + relative fluorescence intensity (24 h: 17.35 ± 1.84; 48 h: 23.21 ± 1.4, 72 h: 25.16 ± 1.33, 33.93 ± 3.9, n = 5; mean ± SD; student’s t-test with p-value). Scale bar 20 μm