Glycated adducts induce mesothelial cell transdifferentiation: role of glucose and icodextrin dialysis solutions.
BACKGROUND
In peritoneal dialysis (PD), the peritoneum is exposed to intermediate Amadori adducts (AmAs) and advanced (AGE) glycated products of proteins. The aim of this study was to test the capacity of AmAs created in different PD solutions (PDSs) to elicit a fibroblast-like transdifferentiation of human peritoneal mesothelial cells (HPMCs) in culture.


METHODS
HPMCs were incubated for 12 hours with AmA obtained by human serum albumin (HSA) incubated for 6 days with commercial 3.86% glucose (Glu), 1.36% Glu and 7.5% icodextrin (Ico) PDS. Mesenchymal (vimentin), epithelial (cadherin) and myofibroblastic (Type I collagen and alpha smooth muscle cell actin [ASMA]) markers were evaluated (RT-PCR, immunostaining and Western blot), as well as TGF-b3 synthesis (ELISA and Western blot).


RESULTS
Ico-PDS was less active than 3.86% and 1.36% Glu-PDS in glycating albumin (p<0.001). AmA-HSA-Glu 3.86% and 1.36% induced a significantly higher increase in vimentin and Type I collagen mRNA expression than AmA-HSA-Ico (p<0.0001). By contrast, AmA-HSA-Glu 3.86% and 1.36% induced a reduction in cadherin mRNA expression which was significantly different from AmA- HSA-Ico (p<0.0001). RT-PCR data were confirmed by immunostaining and Western blot analysis. AmA-HSA-Glu 3.86% and 1.36% induced a significantly higher increase in ASMA mRNA expression than AmA-HSA-Ico (p<0.0001). AmA-HSA-Glu 3.86% and 1.36% stimulated ASMA and TGF-b3 synthesis which were significantly higher than AmA-HSA-Ico (p<0.001 and p<0.01, respectively).


CONCLUSIONS
Our data suggest that Glu-PDS, but not Ico-PDS, can turn on the fibroblastic-like transdifferentiation in HPMCs, and this mechanism may result in peritoneal sclerosis.
Conti
Giovanni
G
Nephrology, Dialysis and Transplantation Unit, Regina Margherita Hospital, Turin, Italy.
Amore
Alessandro
A
Cirina
Paola
P
Peruzzi
Licia
L
Balegno
Sabrina
S
Coppo
Rosanna
R
D000199:Actins / Q000378:metabolism; D015820:Cadherins / Q000378:metabolism; D054338:Cell Transdifferentiation / Q000187:drug effects*; D002478:Cells, Cultured; D024042:Collagen Type I / Q000378:metabolism; D015314:Dialysis Solutions; D004847:Epithelial Cells / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D005347:Fibroblasts / Q000166:cytology; D005936:Glucans / Q000494:pharmacology*; D005947:Glucose / Q000494:pharmacology*; D017127:Glycation End Products, Advanced / Q000378:metabolism; D006801:Humans; D000077607:Icodextrin; D010530:Peritoneal Dialysis; D010537:Peritoneum / Q000166:cytology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012709:Serum Albumin / Q000494:pharmacology*; D053782:Transforming Growth Factor beta3 / Q000096:biosynthesis; D014746:Vimentin / Q000378:metabolism; D000093423:Glycated Serum Albumin
D000199:Actins; D015820:Cadherins; D024042:Collagen Type I; D015314:Dialysis Solutions; D005936:Glucans; D017127:Glycation End Products, Advanced; D012709:Serum Albumin; D053782:Transforming Growth Factor beta3; D014746:Vimentin; D000077607:Icodextrin; D005947:Glucose; D000093423:Glycated Serum Albumin