Lipid Droplets, Perilipins and Cytokeratins – Unravelled Liaisons in Epithelium-Derived Cells
Figure 1
Laser scanning immunofluorescence microscopy of lipid droplets (LDs) in cultured hepatocellular carcinoma cell line PLC.
(a–f; green) Normal cells after 2% formaldehyde fixation and incubation with various newly generated antibodies against PLIN proteins. (a′–f′; red) Oleic acid (OA; 3 h) stimulated cells. Numerous LDs could be detected by monoclonal antibodies (mabs) AP125 (adipophilin; a,a′), TIP47.49.19 (TIP47; b,b′), MLDP-453 (MLDP; f′) and polyclonal antibodies (pabs) Adipo-hCT (adipophilin; d,d′), TIP47-hCT (TIP47; e), TIP47-hNT (TIP47; e′), S3-12-hNT (S3-12; c, c′), MLDP-hCT (MLDP; f). Note: Distribution and sizes of LDs in individual cells might differ slightly in normal cells, depending on the growth phase, cell division status or addition of fresh culture media. (a,a′,d,d′) Adipophilin antibodies stained larger LDs while other PLIN antibodies, especially when compared to the S3-12 staining (c), detected numerous tiny LDs. Note in addition: Short OA treatment changed adipophilin and TIP47 staining in many cells (a,a′,b,b′,d,d′,e,e′). Staining appearance switched in many cells towards larger spots and ring-like structures. In contrast S3-12 and MLDP staining was not visibly influenced by OA treatment (c,c′,f,f′). Differences in sizes seen with TIP47 and MLDP staining upon OA treatment are highlighted by inserts (e′′, f′′). These data indicate that differently reacting LD populations might exist within individual cells. DAPI (blue) was used to stain the nuclei. Bars: 10 µm.