Electroporation-mediated PDGF receptor-IgG chimera gene transfer ameliorates experimental glomerulonephritis.
BACKGROUND
Mesangial cell proliferation and phenotypic alteration occur in an early phase of glomerular injury and precede increased extracellular matrix accumulation. A critical growth factor responsible for mesangial proliferation is platelet-derived growth factor (PDGF), which has proved to be a potent mitogen.


METHODS
We generated a chimeric cDNA encoding an extracellular domain of the beta-PDGF receptor fused with IgG-Fc, termed PDGFR/Fc, and examined the feasibility of gene therapy targeting PDGF using PDGFR/Fc.


RESULTS
Chimeric PDGFR/Fc molecule completely inhibited the tyrosine phosphorylation of beta-PDGF receptors and cellular proliferation induced by PDGF in vitro. We then introduced the PDGFR/Fc expression vector into the muscle of anti-Thy-1 model of glomerulonephritic rats by electroporation. The plasma concentration of chimeric PDGFR/Fc levels was 244.4 +/- 89.8 ng/mL four days after transfection. On day 5, PDGFR/Fc gene transfer significantly reduced the number of PCNA-positive cells and glomerular cell numbers by 59.6 and 23.2%, respectively. Northern blot analysis demonstrated that glomerular mRNA levels of alpha-smooth muscle action, transforming growth factor-beta 1, and type I collagen were also suppressed on days 5 and 7 by the PDGFR/Fc transfection. There was a significant reduction in the matrix score of the transfected nephritic rats (2.91 +/- 0.75 and 2.06 +/- 0.95; disease control group vs. treated group, P < 0.001).


CONCLUSIONS
These results suggest that gene therapy by the manipulation of PDGF action using electroporation-mediated PDGFR/Fc gene transfer to the skeletal muscle might be a useful treatment for mesangioproliferative glomerulonephritis.
Nakamura
H
H
Department of Internal Medicine and Therapeutics, Osaka University Graduate School of Medicine, Suita, Japan.
Isaka
Y
Y
Tsujie
M
M
Akagi
Y
Y
Sudo
T
T
Ohno
N
N
Imai
E
E
Hori
M
M
D000199:Actins / Q000235:genetics; D000818:Animals; D002455:Cell Division / Q000502:physiology; D002478:Cells, Cultured; D003094:Collagen / Q000235:genetics; D018274:Electroporation; D005109:Extracellular Matrix / Q000378:metabolism / Q000473:pathology; D015870:Gene Expression; D018014:Gene Transfer Techniques; D015316:Genetic Therapy / Q000379:methods*; D005920:Glomerular Mesangium / Q000473:pathology / Q000502:physiology; D005921:Glomerulonephritis / Q000378:metabolism / Q000473:pathology / Q000628:therapy*; D006801:Humans; D007074:Immunoglobulin G / Q000235:genetics*; D008297:Male; D018482:Muscle, Skeletal / Q000502:physiology; D010641:Phenotype; D010766:Phosphorylation; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D020797:Receptor, Platelet-Derived Growth Factor beta / Q000235:genetics* / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics; D018800:Thy-1 Antigens; D016212:Transforming Growth Factor beta / Q000235:genetics; D053773:Transforming Growth Factor beta1; D014443:Tyrosine / Q000378:metabolism
D000199:Actins; D007074:Immunoglobulin G; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; C508960:TGFB1 protein, human; C508962:Tgfb1 protein, rat; D018800:Thy-1 Antigens; D016212:Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1; D014443:Tyrosine; D003094:Collagen; D020797:Receptor, Platelet-Derived Growth Factor beta