Hepatocyte growth factor gene therapy retards the progression of chronic obstructive nephropathy.
BACKGROUND
Unilateral ureteral obstruction (UUO) is characterized by progressive tubular atrophy and interstitial fibrosis. Rupture of the balance between cell proliferation and apoptosis plays a critical role in renal atrophy. Hepatocyte growth factor (HGF) is a cytokine function on cell survival and tissue regeneration. We studied the effects and possible mechanisms of HGF gene therapy on tubular cell survival and anti-fibrosis in chronic obstructed nephropathy.


METHODS
An in vivo transfection procedure of repeatedly transducing skeletal muscles with the HGF gene using liposomes containing the hemagglutinating virus of Japan (HVJ liposome) was tested on UUO rats. Expression of HGF and c-Met were examined by in situ hybridization, ELISA, or immunohistochemical staining. Interstitial fibrosis and macrophage infiltration were evaluated by Masson's Trichrome staining, alpha-smooth muscle actin and ED-1 immunostaining. Cell survival indices including proliferating cell nuclear antigen (PCNA), Bcl-2, Bcl-xL and Bax were measured by immunohistochemistry and Western blots. Apoptosis was determined by the TUNEL method.


RESULTS
After HVJ-HGF gene transfer, endogenous HGF and c-Met were up-regulated in UUO kidneys. Renal fibrosis, macrophage infiltration and tubular atrophy were suppressed both at day 14 and 28 after UUO (P < 0.05 or 0.01). Tubular cell proliferation was activated while apoptosis was inhibited, especially at the late stage of UUO. Bcl-2 was enhanced in the HGF-transfected UUO rats, while no changes of Bcl-xL and Bax were found.


CONCLUSIONS
In vivo HGF gene transfection retards the progression of chronic obstructed nephropathy and protects tubular cell survival in the long-term UUO model. Bcl-2 rather than Bcl-xL or Bax may contribute to the anti-apoptotic function of HGF.
Gao
Xiaojie
X
Department of Pediatrics, Hyogo College of Medicine, 1-1 Mukogawacho, Nishinomiya, Hyogo 663-8501, Japan.
Mae
Hiromu
H
Ayabe
Nobuhiko
N
Takai
Toru
T
Oshima
Keisuke
K
Hattori
Masuji
M
Ueki
Takahiro
T
Fujimoto
Jiro
J
Tanizawa
Takakuni
T
D000818:Animals; D017209:Apoptosis; D001284:Atrophy; D002455:Cell Division; D018450:Disease Progression; D005355:Fibrosis; D015870:Gene Expression; D015316:Genetic Therapy; D017228:Hepatocyte Growth Factor / Q000235:genetics*; D007674:Kidney Diseases / Q000473:pathology / Q000628:therapy*; D007684:Kidney Tubules / Q000473:pathology; D008264:Macrophages / Q000473:pathology; D008297:Male; D011518:Proto-Oncogene Proteins / Q000235:genetics; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics; D019859:Proto-Oncogene Proteins c-met / Q000235:genetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D014162:Transfection; D014517:Ureteral Obstruction / Q000473:pathology / Q000628:therapy*; D051028:bcl-2-Associated X Protein; D051020:bcl-X Protein
C494828:Bax protein, rat; C494813:Bcl2l1 protein, rat; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D051028:bcl-2-Associated X Protein; D051020:bcl-X Protein; D017228:Hepatocyte Growth Factor; D019859:Proto-Oncogene Proteins c-met