BACKGROUND: Primary hyperoxaluria type-1 (PH1) is an autosomal recessive disease characterized by excessive oxalate production by hepatocytes caused by the deficiency of peroxisomal alanine-glyoxylate aminotransferase (AGT) activity. Persistent hyperoxaluria causes nephrocalcinosis and urolithiasis, leading to renal failure, followed by tissue oxalosis with life-threatening complications. Combined liver-kidney transplantation is the only definitive treatment of PH1. Hepatocyte transplantation, which is much less invasive, could have offered an attractive alternative. However, because the AGT-deficient hepatocytes overproduce oxalate, a large fraction of the mutant host hepatocytes must be replaced by AGT-competent cells, which is beyond the capacity of current hepatocyte transplantation procedures. Here, we have evaluated a preparative irradiation-based method of liver repopulation in an Agxt-deleted mouse model of PH1 (Agxt-/-). MATERIALS AND METHODS: Hepatocytes (10(6) viable cells) isolated from congeneic mice ([ROSA]26 C57BL/6J) expressing Escherichia coli beta-galactosidase were transplanted into Agxt-/- mice by intrasplenic injection. The preparative regimen consisted of X-irradiation of the host liver and mitotic stimulation of the hepatocytes by adenovector-based expression of hepatocyte growth factor. RESULTS: The procedure resulted in progressive replacement of the mutant host hepatocytes with the AGT-competent hepatocytes, leading to correction of urinary oxalate excretion. Oral ethylene glycol challenge (0.7% for 1 week) resulted in nephrocalcinosis and microlithiasis in untreated Agxt-/- mice, but not in the mice after hepatic repopulation. CONCLUSION: The results indicate that hepatocyte transplantation after appropriate preparative regimens may permit sufficient repopulation of the liver to ameliorate hyperoxaluria, and therefore should be evaluated further as a potential treatment of PH1.
BACKGROUND:Primary hyperoxaluria type-1 (PH1) is an autosomal recessive disease characterized by excessive oxalate production by hepatocytes caused by the deficiency of peroxisomal alanine-glyoxylate aminotransferase (AGT) activity. Persistent hyperoxaluria causes nephrocalcinosis and urolithiasis, leading to renal failure, followed by tissue oxalosis with life-threatening complications. Combined liver-kidney transplantation is the only definitive treatment of PH1. Hepatocyte transplantation, which is much less invasive, could have offered an attractive alternative. However, because the AGT-deficient hepatocytes overproduce oxalate, a large fraction of the mutant host hepatocytes must be replaced by AGT-competent cells, which is beyond the capacity of current hepatocyte transplantation procedures. Here, we have evaluated a preparative irradiation-based method of liver repopulation in an Agxt-deleted mouse model of PH1 (Agxt-/-). MATERIALS AND METHODS: Hepatocytes (10(6) viable cells) isolated from congeneic mice ([ROSA]26 C57BL/6J) expressing Escherichia coli beta-galactosidase were transplanted into Agxt-/- mice by intrasplenic injection. The preparative regimen consisted of X-irradiation of the host liver and mitotic stimulation of the hepatocytes by adenovector-based expression of hepatocyte growth factor. RESULTS: The procedure resulted in progressive replacement of the mutant host hepatocytes with the AGT-competent hepatocytes, leading to correction of urinary oxalate excretion. Oral ethylene glycol challenge (0.7% for 1 week) resulted in nephrocalcinosis and microlithiasis in untreated Agxt-/- mice, but not in the mice after hepatic repopulation. CONCLUSION: The results indicate that hepatocyte transplantation after appropriate preparative regimens may permit sufficient repopulation of the liver to ameliorate hyperoxaluria, and therefore should be evaluated further as a potential treatment of PH1.
Authors: Jianqiang Ding; Govardhana R Yannam; Namita Roy-Chowdhury; Tunda Hidvegi; Hesham Basma; Stephen I Rennard; Ronald J Wong; Yesim Avsar; Chandan Guha; David H Perlmutter; Ira J Fox; Jayanta Roy-Chowdhury Journal: J Clin Invest Date: 2011-04-18 Impact factor: 14.808
Authors: Kristen J Skvorak; Elizabeth J Hager; Erland Arning; Teodoro Bottiglieri; Harbhajan S Paul; Stephen C Strom; Gregg E Homanics; Qin Sun; Erwin E W Jansen; Cornelis Jakobs; William J Zinnanti; K Michael Gibson Journal: Biochim Biophys Acta Date: 2009-08-19
Authors: Kristen J Skvorak; Harbhajan S Paul; Kenneth Dorko; Fabio Marongiu; Ewa Ellis; Donald Chace; Carolyn Ferguson; K Michael Gibson; Gregg E Homanics; Stephen C Strom Journal: Mol Ther Date: 2009-05-12 Impact factor: 11.454
Authors: Marc Benderitter; Fabio Caviggioli; Alain Chapel; Robert P Coppes; Chandan Guha; Marco Klinger; Olivier Malard; Fiona Stewart; Radia Tamarat; Peter van Luijk; Charles L Limoli Journal: Antioxid Redox Signal Date: 2014-02-03 Impact factor: 8.401