*2.9. Boyden Chamber Invasion Assay*

To test the e ffect of HLP on the in vitro invasiveness of VSMC-treated TNFα, a modified Boyden chamber (Neuro Probe, Cabin John, MD, USA) invasion assay coating with a layer of Matrigel (25 mg/50 mL; Sigma-Aldrich, St Louis, MO, USA) was used [23], and was applied to polycarbonate membrane filters with an 8.0 μm pore size (Nucleopore, Pleasanton, CA, USA). Afterwards, the membrane was fixed with methanol, and then stained with 10% Giemsa (Sigma-Aldrich, St Louis, MO, USA). The image of cells invaded through the membrane was capture and counted under the light microscope.
