Journal: Nature
Article Title: Sleep-dependent clearance of brain lipids by peripheral blood cells
doi: 10.1038/s41586-025-10050-w
Figure Lengend Snippet: a-c . Analysis of lipid classes in hemocytes. A lipidomic analysis pipeline utilizing Multiple Reaction Monitoring (MRM) profiling with an Agilent 6495 C Triple Quadrupole Mass Spectrometer (MS) followed by automated data analysis. The data are depicted as a boxplot representation of the intensity distribution of various lipid classes detected in wild-type hemocyte samples ( HmlΔ>GFP/ +, N = 3) using multiple reaction monitoring (MRM)-based lipidomics. The full intensity distribution across lipid classes, highlighting variations in signal intensities, is shown (left). On the right is a zoomed-in view providing a more detailed comparison of lipid classes with lower intensity signals (right). Each lipid class is color-coded, and individual data points represent detected lipid species ( b ). Diacylglycerols (DAGs), triacylglycerols (TAGs), and lipid classes in hemocytes are depicted by MRM intensity distribution. Pie charts represent the relative intensity distribution of DAG species categorized by fatty acid (FA) chain composition across three biological replicates (N1, N2, N3) (top). The relative intensity distribution of TAG species is indicated by FA chain composition, showcasing the diversity of FA chains (middle). Predominant lipid classes detected are indicated by lipid class distribution within the lipidomic profile (bottom). The color legends correspond to the FA chain composition and lipid classes in each panel ( c ). The box represents the interquartile range (25%–75% percentiles) and the line inside box means median. d-g . Ex vivo culture of hemocytes with neutral or oxidized LDL. Neutral LDL (red) were barely observed within or attached to wild-type (left, green, HmlΔ>GFP/+, n = 30) or eater mutant (right, green, HmlΔ>GFP/+, eater 1 , n = 30) hemocytes ( d ). Quantification of the bound neutral LDL on the hemocytes. Bounded amount was normalized to CantonS hemocytes ( e ). Oxidized LDL (OxLDL) (red) were observed inside the wild-type hemocytes (left, green, HmlΔ>GFP/+, n = 30) and eater mutants (right, green, HmlΔ>GFP/+, eater 1 , n = 30) ( f ). Quantification of the bound oxidized LDL in the hemocytes. Bounded amount was normalized to CantonS hemocytes ( g ). Two-sided Mann-Whitney test was performed for data analysis. h . Quantification of daytime and nighttime sleep time in the crq mutant ( CrqΔ ) fly (top; male, bottom; female). n = 15 for CantonS , n = 16 for CrqΔ males, n = 15 for CantonS , n = 16 for CrqΔ females. Two-sided Mann-Whitney test was performed for data analysis. i-j . Immunoprecipitation of acetylated GLaz from wild-type or eater mutant brain. GLaz expression level in the wild-type ( CantonS , C.S, n = 4) or eater mutant ( eater 1 , n = 4) is similar in the lysate. The level of acetylated-GLaz is also similar ( i ). This is supported by quantification of acetylated-GLaz levels ( j ). IB: immunoblot. IP: Immunoprecipitation. Lys AC : acetylated lysine. Tub: alpha tubulin. Two-sided Mann-Whitney test was performed for data analysis. n represents biologically independent experiments. k . Measurement of NADH levels in eater mutant ( eater 1 , n = 8) and wild-type ( CantonS, n = 8) heads. Two-sided Unpaired t test was performed for data analysis. n represents biologically independent experiments. l . Graphs comparing total sleep time in female wild-type ( Repo-GeneSwitch(G.S)/+ ), sirtuin overexpression ( Repo-GeneSwitch(G.S) UAS-Sirt1/+ ), and eater mutant with sirtuin overexpression ( Repo-GeneSwitch(G.S) UAS-Sirt1/+, eater 1 ) in glial cells. The red shade indicates the sleep data for flies fed with RU486. n = 15, 12, 16, 15, 11, and 12. From left to right. Two-sided Tukey’s multiple comparisons test was performed for data analysis. m . Visualization of ROS using fluorescence probes in the brain. ROS dyes (left, MitoSox, right, DHE) were co-localized with cortex glial cell marker (green, NP2222-Gal4 UAS-mCD8GFP/+ ). n . Staining of cleaved Dcp1 as a cell-death marker in the fly brain. There are no differences in Dcp1 staining (green) in wild-type ( CantonS , left) and eater mutants ( eater 1 , right). Glial cell was visualized by repo antibody (magenta). ns: not significant (p > 0.01); *p < 0.1; **p < 0.01, ***p < 0.001. ****p < 0.0001. Bars in graphs: the median. White scale bar, 100 μm unless otherwise indicated. n represents biologically independent samples except ss(j), (k). Schematic in a was created using BioRender ( https://biorender.com ).
Article Snippet: The following primary antibodies were used: α-NimC1 (a gift from I. Ando; 1:100), α-brp (Developmental Studies Hybridoma Bank (DSHB), catalogue no. nc82; 1:100), α-Repo (DSHB, catalogue no. 8D12; 1:100), α-cleaved dcp1 (Cell Signaling, catalogue no. 9578S; 1:100), Oil-Red O (Sigma, catalogue no. O9755) and BODIPY 493/503 (Fisher, catalogue no. D3922, 1:1,000).
Techniques: Targeted Proteomics, Mass Spectrometry, Comparison, Ex Vivo, Mutagenesis, MANN-WHITNEY, Immunoprecipitation, Expressing, Western Blot, Over Expression, Fluorescence, Marker, Staining