Suitability of LLC-PK1 pig kidney cells for the study of drug action on renal cell cholesterol uptake: Identification and characterization of low-density lipoprotein receptors

Introduction: The purpose of this study was to identify and characterize the presence of low-density lipoprotein receptors (LDLr) in LLC-PK1 cells. Methods: LLC-PK1 cells were assessed for the presence of LDLr by conducting dose-response, LDL specific binding and competitive studies with DiI-LDL, and Western blot and RT-polymerase chain reaction (PCR) analyses. Assay conditions with IgG-C7, a monoclonal antibody (mAb) to the LDLr, were optimized, including temperature, preincubation time, and concentration in LLC-PK1 cells. Results: LLC-PK1 cells express LDL receptors as determined by LDL specific and competitive binding studies and Western blot and RT-PCR analysis (specific binding 0.5 ng DiI-LDL/μg of cellular protein). Discussion: Taken together, these findings confirm the presence of LDL receptors on LLC-PK1 cells and support the appropriateness of using these cells in studies involving renal cell cholesterol uptake and metabolism.