The use of human embryonic kidney (HEK 293) cells to enhance characterization of the LMX1B pathway

LMX1B is a homeodomain transcription factor critical to kidney development and glomerular filtration. In humans, LMX1B haploinsufficiency causes a condition known as Nail Patella syndrome (NPS). Individuals with NPS typically have under developed nails, absent patellae, and impaired kidney function. In Lmx1b knockout mice, the absence of Lmx1b function disrupts glomerular filtration and abates urine production. The molecules targeted by LMX1B that regulate glomerular development and function, however, are poorly characterized. Immortalized human embryonic kidney (HEK 293) cells provide a potential tool for high-throughput identification of LMX1B targets and an in vitro system for dissecting the functional role of targets. Thus, we characterized the known LMX1B pathway in HEK 293 cells and evaluated sites of LMX1B binding. We demonstrate the expression of LMX1B and its renal targets, COLLAGEN 4 ALPHA 4 and PODICIN in HEK 293 cells by RT-PCR. Protein expression of LMX1B was verified by w...