Journal: bioRxiv

Article Title: mRNA Treatment Rescues Niemann-Pick Disease Type C1 in Patient Fibroblasts

doi: 10.1101/2022.02.21.479058

Figure Lengend Snippet: (A) Overview of the rationale behind mRNA-based treatment of NP-C1 disease. (B) NPC1 and Hoechst 33342 staining in healthy fibroblasts (GM03652), Lipofectamine-treated patient fibroblasts (GM18393), and GM18393 patient fibroblasts treated with 50 ng of M1ψTP-modified NPC1 mRNA. Cells were seeded at a density of 3000 per well and imaged 24 h after treatment. Images are representative of three independent experiments. (C) Quantification of NPC1 staining from the experiment in (B), as measured by average NPC1 fluorescence per cell (cumulative NPC1 fluorescence was divided by the total number of cells identified via Hoescht staining, using the PerkinElmer Harmony high-content analysis software). Data are mean ± s.d. of three technical replicates (from one representative of three independent experiments), encompassing 7 imaging fields per well and >300 cells per treatment condition. (D) Quantification of total and unesterified cholesterol levels in healthy cells, Lipofectamine-treated GM18393 cells, and GM18393 cells treated with 50 ng NPC1 M1ψTP mRNA, after a 48 h incubation in lipoprotein-deficient serum followed by either a 6 h incubation with 50 μg/ml LDL or a further 6 h incubation with lipoprotein-deficient serum to establish a baseline control. Total and unesterified cholesterol levels were assayed using the Amplex Red Cholesterol Assay Kit. Data are mean ± s.d. of two independent experiments. (E) Filipin and Lysotracker Red DND-99 staining in healthy cells, Lipofectamine-treated GM18393 cells, and 50 ng mRNA-treated GM18393 cells after a 48 h incubation in lipoprotein-deficient serum followed by 6 h incubation with 50 μg/ml LDL. Images are representative of three independent experiments. (F) Quantification of filipin staining from the experiment in (E), as measured by average filipin fluorescence per well. Data are mean ± s.d. of three technical replicates (from one representative of three independent experiments), encompassing 9 imaging fields per well and >600 cells per treatment condition. (G) Quantification of lysosome size from Lysotracker Red staining in (E), using the PerkinElmer Harmony high-content analysis software. Data are mean ± s.d. of two technical replicates (from one representative of three independent experiments), encompassing 9 imaging fields per well and >300 cells per treatment condition. In (C), (F) and (G), * P < 0.05, ** P < 0.01 by ordinary one-way ANOVA followed by a Dunnett’s multiple comparisons test. In (D), **** P < 0.0001 by two-way ANOVA followed by a Tukey’s multiple comparisons test.

Article Snippet: After a further 6 h, intracellular levels of unesterified cholesterol and total cholesterol were separately assayed using the Amplex Red Cholesterol Assay Kit (Promega), following the manufacturer’s instructions.

Techniques: Staining, Modification, Fluorescence, High Content Screening, Software, Imaging, Incubation, Amplex Red Cholesterol Assay

Journal: Nature Communications

Article Title: Molecular basis for the catalytic mechanism of human neutral sphingomyelinases 1 (hSMPD2)

doi: 10.1038/s41467-023-43580-w

Figure Lengend Snippet: a Hydrolysis of sphingomyelin by sphingomyelinases. b Relative enzyme activity of wild type hSMPD2 and hSMPD3 measured using the Amplex Red Sphingomyelinase Assay Kit. Data shown are mean +/− SEM ( n = 4, biological replicates). Source data are provided as a Source Data file. c Cryo-EM map of the high-resolution hSMPD2 structure from three different views. The two protomers are indicated in orange and purple. d Ribbon representation of hSMPD2 from a side view. The two protomers are indicated in orange and purple. e Cylindrical representation of a hSMPD2 protomer. Different regions are indicated with different colors. f Schematic representation of the secondary structure of hSMPD2.

Article Snippet: hSMPD2 activity was quantified with the Amplex Red Sphingomyelinase Assay Kit (Cat# A12220; Thermal Scientific) at 37 °C, in which the 10-acetyl-3,7-dihydroxyphenoxzazine was utilized to monitor sphingomyelinase activity.

Techniques: Activity Assay, Cryo-EM Sample Prep