Journal: Scientific reports

Article Title: Histamine stimulates human microglia to alter cellular prion protein expression via the HRH2 histamine receptor.

doi: 10.1038/s41598-024-75982-1

Figure Lengend Snippet: Fig. 3. Histamine stimulates HMC3 cells to alter cytokine production and intracellular calcium levels, but not metabolic activity or Iba-1 expression. (A-B) HMC3 cells were stimulated with (A) histamine (0.1 µM – 1000 µM) or (B) LPS or left untreated for 24 hours and metabolic activity was measured by a reduction in XTT. The data are presented as the means ± SEMs (N = 6). (C-D) HMC3 cells were stimulated by histamine (10 µM, 100 µM, or 1000 µM), LPS (1 µg/mL), or left untreated for 24 hours, and (C) IL-8 and (D) IL-6 were measured by sandwich ELISA. Data are presented as the mean ± SEM (N = 9) and statistical significance was measured via one-way ANOVA and Dunnett’s multiple comparison post-hoc analysis relative to untreated (UT) cells. p ≤ 0.05 (*), p ≤ 0.01 (**), p ≤ 0.001 (***), p ≤ 0.0001 (****). (N = 4). (E) HMC3 cells were stimulated by histamine (100 µM) (blue) or 4-bromo-A23187 (1 µM) (orange) and intracellular calcium was measured via fura-2 AM dye which increases the 340/380 fluorescence ratio when bound to calcium ions. (F-H) Fluorescence microscopy images of HMC3 cells labelled with Hoechst 33342 (Hoechst) (blue) and Iba-1 (red) under (F) untreated conditions and following 24 hours treatment with (G) LPS and (H) histamine. Images are representative of four independent experiments using a 20× objective and a Leica Stellaris 5 microscope.

Article Snippet: Images were acquired using an Olympus IX81 inverted microscope with a 20× objective and a Leica Stellaris 5 laser scanning confocal microscope with a 60× oil objective.

Techniques: Activity Assay, Expressing, Sandwich ELISA, Comparison, Fluorescence, Microscopy

Journal: Scientific reports

Article Title: Histamine stimulates human microglia to alter cellular prion protein expression via the HRH2 histamine receptor.

doi: 10.1038/s41598-024-75982-1

Figure Lengend Snippet: Fig. 7. Immunofluorescence detection of surface PrPCexpression in HMC3 cells treated with histamine and LPS. Representative fluorescence microscopy images of HMC3 labelled with Hoechst 33342 (blue) and anti- PrPC POM2 (red) under (A) untreated conditions or after 24 hours of stimulation by (B) histamine or (C) LPS. Images are representative of three independent experiments using a 20× objective and a Leica Stellaris 5 microscope.

Article Snippet: Images were acquired using an Olympus IX81 inverted microscope with a 20× objective and a Leica Stellaris 5 laser scanning confocal microscope with a 60× oil objective.

Techniques: Immunofluorescence, Fluorescence, Microscopy