[Protective effect of heme oxygenase-1 induction in vivo to pancreas islet xenograft].
OBJECTIVE
To study the protective effect of islet xenograft and its possible mechanism of high expression of heme oxygenase-1 (HO-1) in donor pancreas islet induced by cobalt protoporphyrin (CoPP).


METHODS
Male SD rats and C57BL/6 mouse were used as donors and recipients respectively. Donors were divided into 3 groups according to different pretreatment 24 hours before donation: control group (injected intraperitoneally with NaCl), induce group [injected intraperitoneally with cobalt-protoporphyrin (CoPP)], block group (injected intraperitoneally with CoPP and zinc protoporphyrin simultaneously). A modified approach was used for islet isolation.Recipients were rendered diabetic by intraperitoneal injection of streptozotocin. Islets were transplanted into mouse subrenal capsule. Postoperative mouse glycemia were monitored daily and normoglycemia time was compared among each group. The receptor mouse serum IL-10 was detected by ELISA approach, and real-time PCR was used to check the expression of IL-10 mRNA in islet graft tissues. The graft tissues were observed for the lymphocyte infiltration after HE staining.


RESULTS
Diabetes mice accepted islets untreated, induced or blocked maintained the euglycemia for (9.3 +/- 1.4), (16.3 +/- 1.5) and (9.7 +/- 1.0) d respectively. The xeno-islets presented HO-1 over-expression survived much longer than that absent (P < 0.05), it was no significance between control group and block group (P > 0.05). The mouse islet serum IL-10 content after induction was (73.0 +/- 9.7) pg/ml, significantly higher than (30.6 +/- 3.9) pg/ml of the untreated group and (32.1 +/- 5.9) pg/ml of the blocked group (P < 0.05), there was no difference between control group and block group (P > 0.05). Moreover, the IL-10 mRNA expression up-regulated statistic significantly in HO-1 induced islet xeno-graft. Pathological examination showed that the graft lymphocyte infiltration of the induced group was obviously less serious than the other two groups.


CONCLUSIONS
The higher expression of HO-1 induced by CoPP in vivo would significantly prolong graft survival time and its mechanism could be related to immune modulation of IL-10.
Su
Chang
C
Department of Surgery, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200025, China.
Chen
Xi
X
Zhang
Zheng-yun
ZY
Gu
Wei-qiong
WQ
Zhang
Ming-jun
MJ
Zhou
Guang-wen
GW
Li
Xiao-ying
XY
Ning
Guang
G
Li
Hong-wei
HW
D000818:Animals; D003921:Diabetes Mellitus, Experimental / Q000378:metabolism / Q000473:pathology / Q000601:surgery; D006085:Graft Survival; D051547:Heme Oxygenase-1 / Q000187:drug effects / Q000378:metabolism*; D016753:Interleukin-10 / Q000378:metabolism; D007515:Islets of Langerhans / Q000378:metabolism / Q000473:pathology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D016035:Pancreas Transplantation; D011524:Protoporphyrins / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013370:Subrenal Capsule Assay; D014183:Transplantation, Heterologous
D011524:Protoporphyrins; D016753:Interleukin-10; C007095:cobaltiprotoporphyrin; D051547:Heme Oxygenase-1