IMMUNOHISTIOCHEMISTRY: NELL1

NELL-1 IS A GENE NAMED AFTER ITS SIMILARITY TO A GENE NEL THAT IS STRONGLY EXPRESSED IN NEURAL TISSUE ENCODING A PROTEIN WITH EGF-LIKE REPEATS.10 NEL EXPRESSION IS PRESENT IN ALL CHICK TISSUES, AND THE HIGHEST EXPRESSION WAS IN THE BRAIN. NONNEURAL TISSUES SUCH AS LIVER AND KIDNEY EXPRESS VERY LOW LEVELS OF NEL.1 SINCE THEN, TWO GENES HOMOLOGOUS TO NEL, NELL-1, AND NELL-2 HAVE BEEN IDENTIFIED. NELL-1 ENCODES A 90-KDA SECRETED PROTEIN OF 810 AMINO ACIDS AND CONTAINS CONSERVED MOTIFS INCLUDING A SECRETORY SIGNAL PEPTIDE, NH2-TERMINAL THROMBOSPONDIN-1 LIKE MOLECULE (TSPN), COILED-COIL DOMAIN, 4 VON WILLEBRAND TYPE DOMAINS, AND 6 EGF-LIKE REPEATS. IN THE KIDNEY, NELL-1 EXPRESSION IS HIGHER IN TUBULES WHILE IT IS BARELY DETECTABLE IN THE GLOMERULI ALTHOUGH 5% TO 25% OF GLOMERULAR CELLS EXPRESS NELL-1 AT THE MRNA LEVEL.2 NELL 1 ASSOCIATED MEMBRANOUS GLOMERULOPATHY (MGN) HAS BEEN CHARACTERIZED AFTER DETAILED MORPHOLOGICAL , PROTEOMIC AND MOLECULAR ANALYSIS OF PLA2R AND THSD7A (THROMBOSPONDIN)