The effects of receptor associated protein C-terminal on nephrin in Heymann nephritis

Abstract

Objective To explore the role of C-terminal antigenic determinant of Heymann nephritis receptor associated protein(RAP)in Heymann nephritis pathogenesis.Methods The full-length RAP and C-terminal polypeptide karyogamy expression vector Was constructed by PCR and molecular cloning to express fusion protein.Antiserum to the full-length RAP and C-terminal fusion protein Was prepared and orientated in kidney tissue by immunofluorescence.Two kinds of Heymann nephritis animal models were made with these antisera.We measured the 24 h urine protein quantitation,the expression and distribution of nephrin in kidney tissue and compared the data between the two groups.Results Recombinant protokaryon expression vector pGEX-dT-1-RAP1083/324 was successfully constructed and expressed the full-length RAP(70×103)and C-terminal fusion protein(40×103).We found that two kinds of prepared relevant antisera strongly expressod in the renal tubular epithelial cell by immunofluorescence.Heymann nephritis animal models were also successfully made.The 24 h urine protein quantitation in two model rats groups were (21.31±4.15)mg and(19.05±3.72)mg respectively.The 24 h urine protein quantitation in model groups were higher than that in the normal group(P<0.01).The expression of nephrin in RAP1083 induced model rats' glomeruhs Was lower than the RAP324 induced group.Conclusion Pathological antigenic determinant exists in the Heymann nephritis RAP C-terminal and Call induce rat Heymann nephritis models.Nephrin expression reduced in two kinds of Heymann nephritis.It indicated that the mechanism of RAP might be related to the low expression of nephrin in glomemhs. Key words: Heymann nephritis; Receptor associated protein; C-terminal; Podocyte; Nephrin