R2: identification of renal potential progenitor/stem cells that participate in the renal regeneration processes of kidney allograft fibrosis.
OBJECTIVE
Many strategies are explored to ameliorate kidney allograft tubular atrophy and interstitial fibrosis (TA/IF), but little progress has been achieved. The latest evidence suggested that CD133+ cell in kidney represent a potential multipotent adult resident stem cell population that may contribute to the renal injury repair. Here we investigate whether the CD133+ cells exist in transplanted renal and exert a growth and self-repair procedure in TA/IF.


METHODS
Allografts from rat kidney transplant models were harvested at 4 weeks, 8 weeks and 12 weeks post transplantation. We performed immunohistochemistry to detect the CD133+ cells and immunofluorescence to detect the co-expression of CD133 or Pax-2 with Ki-67. We furthermore analysed the E-cadherin using serial sections.


RESULTS
CD133+ cells were seldom seen in control kidney, but distributed sporadically in the cortex parenchyma along with the deterioration of TA/IF. The number of CD133+ cell increased after 4 weeks and reached the peak at 8 weeks, then decreased at 12 weeks. From 8 weeks, some new tubules expressing E-cadherin were constructed with CD133+ cells. Almost all the CD133+ cells were Ki-67-positive, but not all the Ki-67+ cells expressed CD133. The rest Ki-67+ cells almost expressed Pax-2.


CONCLUSIONS
Our study reveals that when majority of the tubules are damaged, a self-repair mechanism is evoked by potential adult stem cells to compensate the renal function. Thus, potential adult resident stem cells offer a new avenue for autologous cell therapies in TA/IF.
Bao
Ji
J
Key Laboratory of Transplant Engineering and Immunology, Ministry of Health, West China Hospital, Sichuan University, Chengdu, China.
Tu
Zhidan
Z
Sun
Huaiqiang
H
Luo
Guangheng
G
Yang
Li
L
Song
Jun
J
Qin
Mingxia
M
Shi
Yujun
Y
Bu
Hong
H
Li
Youping
Y
D000071916:AC133 Antigen; D000818:Animals; D015703:Antigens, CD / Q000032:analysis; D003094:Collagen / Q000378:metabolism; D003404:Creatinine / Q000097:blood; D005355:Fibrosis; D006023:Glycoproteins / Q000032:analysis; D007668:Kidney / Q000473:pathology* / Q000502:physiology*; D016030:Kidney Transplantation; D008297:Male; D010455:Peptides / Q000032:analysis; D051381:Rats; D011916:Rats, Inbred F344; D011917:Rats, Inbred Lew; D012038:Regeneration; D013234:Stem Cells / Q000502:physiology*; D014184:Transplantation, Homologous
D000071916:AC133 Antigen; D015703:Antigens, CD; D006023:Glycoproteins; D010455:Peptides; C000606025:Prom1 protein, rat; D003094:Collagen; D003404:Creatinine