A high incidence of WT1 abnormality in bilateral Wilms tumours in Japan, and the penetrance rates in children with WT1 germline mutation.

BACKGROUND: Bilateral Wilms tumours (BWTs) occur by germline mutation of various predisposing genes; one of which is WT1 whose abnormality was reported in 17-38% of BWTs in Caucasians, whereas no such studies have been conducted in East-Asians. Carriers with WT1 mutations are increasing because of improved survival. METHODS: Statuses of WT1 and IGF2 were examined in 45 BWTs from 31 patients with WT1 sequencing and SNP array-based genomic analyses. The penetrance rates were estimated in WT1-mutant familial Wilms tumours collected from the present and previous studies. RESULTS: We detected WT1 abnormalities in 25 (81%) of 31 patients and two families, which were included in the penetrance rate analysis of familial Wilms tumour. Of 35 BWTs from the 25 patients, 31 had small homozygous WT1 mutations and uniparental disomy of IGF2, while 4 had large 11p13 deletions with the retention of 11p heterozygosity. The penetrance rate was 100% if children inherited small WT1 mutations from their fathers, and 67% if inherited the mutations from their mothers, or inherited or had de novo 11p13 deletions irrespective of parental origin (P=0.057). CONCLUSIONS: The high incidence of WT1 abnormalities in Japanese BWTs sharply contrasts with the lower incidence in Caucasian counterparts, and the penetrance rates should be clarified for genetic counselling of survivors with WT1 mutations.

Impact of intestinal transplantation for intestinal failure in Japan.

INTRODUCTION: The prognosis of intestinal failure has improved dramatically in the past few decades with the development of parenteral nutrition (PN). However, PN-dependent patients still have numerous complications. Intestinal transplantation can significantly improve their prognosis and quality of life. We report on the impact of intestinal transplantation for intestinal failure in Japan. METHODS: Intestinal transplantations have been performed in Japan since 1996. Standardized forms were sent to all known intestinal transplantation programs, asking for information on intestinal transplantations performed between 1996 and June 31, 2012. All programs responded. Patient and graft survival estimates were obtained using the Kaplan-Meier method and analyzed with the Wilcoxon statistic. RESULTS: Five institutions provided data on 24 grafts in 21 patients. There were 12 cadaveric and 12 living related donor transplants. Causes of intestinal failure included short gut syndrome (n = 9), intestinal motility function disorders (n = 11), retransplantation (n = 3), and other (n = 1). The overall 1- and 5-year patient survival rates were 86% and 68%, respectively. In cases (n = 15) after 2006, the 1-year patient survival rate was 92%, and the 5-year survival rate was 83%. One- and five-year graft survival rates were 87% and 78%, respectively. More than 80% of all current survivors discontinued PN. CONCLUSIONS: Intestinal transplantation has become an effective therapy for patients with intestinal failure who cannot tolerate PN. After 2006, patient and graft survival rates approached rates associated with standard treatment for end-stage intestinal failure. Further improvements are expected with early referral due to suitable donor organ and pretransplant management.

Conversion to prolonged-release tacrolimus for pediatric living related donor liver transplant recipients.

Prolonged-release tacrolimus allows for once-daily dosing. Although many adult recipients have been switched from standard tacrolimus, prolonged-release tacrolimus has not been popular for pediatric patients despite the potential benefits for medication compliance. We report on prolonged-release tacrolimus for 11 pediatric living related donor liver transplant (LRDLT) recipients. Patients under 18 years of age who were receiving standard tacrolimus-based immunosuppression and steroid taper underwent conversion from standard to prolonged-release tacrolimus. We monitored tacrolimus trough levels and liver function tests (LFTs). We also assessed adverse effects and satisfaction levels for prolonged-release tacrolimus. Mean age at transplantation was 4.3 years. The mean duration of follow-up was 12 months. The ratios of trough levels with prolonged-release vs standard tacrolimus were 0.97, 0.95, and 0.92 at 1, 2, and 4 weeks post conversion, respectively. Two patients discontinued prolonged-release tacrolimus owing to abnormal LFTs and neurological abnormalities, respectively; but symptoms resolved after reconversion. One patient returned to standard tacrolimus and the other was converted to cyclosporine. Once-daily administration satisfied 89% of patients. In the overall assessment, conversion to prolonged-release tacrolimus satisfied all patients. Prolonged-release tacrolimus was useful for pediatric patients after LRDLT. Trough levels after conversion were compatible with those before conversion. Most patients were satisfied with prolonged-release tacrolimus. However, some patients failed conversion because of unexpected responses. Close observation after conversion is required even if patients have previously had an uneventful course on standard tacrolimus.

A national survey of patients with intestinal motility disorders who are potential candidates for intestinal transplantation in Japan.

Intestinal motility disorders are a major cause of intestinal failure. Severe cases such as idiopathic pseudo-obstruction represent life-threatening illnessed. Intestinal transplantation is a treatment for severe motility disorders with irreversible intestinal failure. However, the prevalence of severe motility disorders is unknown. We performed a national survey to identify patients with intestinal motility disorders who require an intestinal transplant. The national survey of 302 institutions treating intestinal motility disorders identified 147 patients treated from 2006 to 2011 at 46 institutions. The mean patient age was 12.1 years (range, 0.3-77.5). The mean age of onset was 3.0 years (range, 0.0-68.8). Diagnoses included chronic idiopathic intestinal pseudo-obstruction (n = 96), Hirschsprung disease (n = 29), megacystis microcolon intestinal hypoperistalsis syndrome (n = 18), and other (n = 6). There were 126 survivors and 21 patients who died during the last 5 years. The mortality rate was 14.3%. Eighty-five percent of patients required parenteral nutrition for more than 6 months, which was defined as irreversible intestinal failure. Among surviving patients with irreversible intestinal failure, 8 (9.4 %) developed hepatic failure with jaundice and 27 (31.8%) 2 or more central vein thromboses. In all, at least 35 patients (41%) with irreversible failure due to intestinal motility disorders may be candidates for transplantation. The prevalence of severe intestinal motility disorders was elucidated in Japan. Severe cases should be referred to transplant centers.

A study of the glycoantigens of neonatal porcine islet-like cell clusters using a lectin microarray.

BACKGROUND: The pig pancreas is considered to be the most suitable source of islets for clinical xenotransplantation. Two types of islet transplantation are: adult pig islets and neonatal porcine islet-like cell clusters (NPCC). However, besides a-Gal expression, differences in glycosylation and xenoantigenicity between both types were not clear so fat to date. In this study, we performed lectin microarray analyses of NPCCs cultured for 1, 5, or 9 days. METHODS: We studied differences in gycoantigens among several kinds of wild-type NPCCs isolated from 1- to 3-day-old neonatal wild-type pigs (Large White/Landrace × Duroc) and cultured for 1, 5 and 9 days in Ham's 10 in the presence of nicotinamide, using a previously published technique. After sonication and centrifugation, supernatant proteins from each islet were labeled with Cy3, applied to a lectin array and scanned with an SC-Profiler for evaluation using an Array Pro Analyzer. RESULTS: The overall signals of NPCC at days 5 and 9, showed almost the same values to most lectins, whereas those on day 1 showed differences, suggesting that the NPCC on day 1 contain immature cells that gradually turn to mature NPCCs in culture.

A cloning of cytidine monophospho-N-acetylneuraminic acid hydroxylase from porcine endothelial cells.

INTRODUCTION: The Hanganutziu-Deicher (H-D) antigen with terminal N-glycolyl neuraminic acid-(NeuGc) is widely distributed in mammalian species including monkeys and apes, but is not found in humans and birds. After the knock out of α1, 3galactosyltransfease, the H-D antigen became a major antigen of the "non-Gal antigen." The expression of NeuGc is controlled by the activity of cytidine monophospho-N-acetylneuraminic acid hydroxylase (CMAH). In this study, molecular cloning of pig CMAH was performed, as the first step in producing H-D knockout pigs. METHODS: A pig endothelial cell line, MYP30, was used. The DNA sequence of pig CMAH was queried in dbEST (NCBI) using the BLAST program to search for cDNA fragments of pig CMAH, based on an alignment analysis of the mouse CMAH sequence. A polymerase chain reaction experiment was performed and candidate cDNA clones were isolated. To obtain the 5'-end and 3'-end of the open reading frame sequence, a 5'-full RACE Core Set and 3'-full RACE Core Set were used. RESULTS: We cloned and characterized the pig CMAH gene. The ATG is located in exon 4, which corresponds to the mouse gene, and the stop codon is in exon 17. In the case of the 5' site of the gene, exon 3 was identified but exons 1 and 2 are still being investigated. On the other hand, exon 18 was newly identified in the 3' site of the gene. CONCLUSION: The results represent useful information for future clinical xenotransplantation studies.

Current status of intestinal transplantation in Japan.

The development of total parenteral nutrition (TPN) has dramatically improved the prognosis of patients afflicted with intestinal failure. However, TPN-related complications, which remain a problem for patients with intestinal failure can be addressed by intestinal transplantation, which can significantly improve their prognosis and quality of life. The first intestinal transplantation in Japan occurred in 1996. Of the 17 intestinal transplantations performed to date, six were obtained from deceased donors and 11 from living donors. The primary indications were: short gut syndrome (n = 8), intestinal function disorder (n = 7), and retransplantation (n = 2). In our experience, the 1-year and 5-year patient survival rates are 87% and 69%. All nine patients receiving transplants in the last 7 years have survived, which seem to be acceptable results for the treatment of intestinal failure. Relatively few intestinal transplantations have been performed to date, mainly due to the lack of national health insurance coverage for the procedure and the ban of the use of donors below 15 years of age. Liver failure patients are also ineligible because liver-intestine or multiorgan transplants are not allowed by current guidelines. Case numbers may increase in the future as the result of allowing for pediatric donors in the new Act on Organ Transplantation, which went into effect in July 2010. We continue to work on reforming national insurance coverage to cover multiorgan transplantations.

Postoperative chylothorax in congenital diaphragmatic hernia.

INTRODUCTION: The mechanisms responsible for postoperative chylothorax in Congenital Diaphragmatic Hernia (CDH) patients remain unclear. The aim of the present study was to examine the clinical features of CDH that may contribute to an association with postoperative chylothorax. MATERIAL AND METHODS: 198 neonates with CDH, in whom surgical repair of a diaphragmatic defect was performed between 1981 and 2008, were retrospectively studied. The patients were divided into 2 groups; patients with postoperative chylothorax (group I, n=11) and patients without postoperative chylothorax (group II, n=187). The clinical findings were compared between group I and group II to investigate potential predictive parameters for an association with chylothorax. Moreover, the clinical findings and treatments were evaluated in patients with chylothorax. RESULTS: 11 of the 198 infants (5.5%) developed a chylothorax. Although the incidence of a prenatal diagnosis was slightly higher in group I, no relationship with other clinical features was found which would indicate the severity of CDH or the occurrence of postoperative chylothorax. Treatment for chylothorax was drainage alone in 2 cases, total parenteral nutrition with drainage in 8 infants and additional intrathoracic OK-432 infusion in 1 patient. No patients required surgical intervention for chylothorax. No recurrences were observed in this patient series. CONCLUSIONS: It was concluded that postoperative chylothorax is not rare in infants after CDH repair. However, no statistically significant predictive parameters for chylothorax were identified, except for the presence of a prenatal diagnosis.

Isolation and sequencing of pig Blm and Ubl-1/SUMO-1 genes that relate to the recombination machinery.

BACKGROUND: The gene knockout technique is important in xenotransplantation research. Herein we have described the molecular cloning of two genes that are candidates to overcome the poor rate of homologous recombination. METHODS: Candidate cDNA fragments were amplified by polymerase chain reaction (PCR) with the corresponding primer sets deduced from a multiple alignment analysis of other mammalian genes from a cDNA library prepared from pig spleen tissue. To obtain the full-length cDNA, a 5'- and 3'-RACE PCR experiments was performed. RESULTS: We successfully isolated the cDNA sequences of two pig genes--BLM, a Bloom's syndrome-related gene, and UBL-1/SUMO-1--which are closely related to homologous recombination events. As a result, we verified the sequences of pig BLM and pig UBL-1/SUMO-1. The nucleic acid and amino acid coding sequence homologies of pig BLM gene with the corresponding human gene were 87.3% and 82.9%, respectively. The nucleic acid and amino acid coding sequence homologies of the pig UBL-1/SUMO-1 gene with the human gene were 96.4% and 100%, respectively. CONCLUSION: Current research into homologous recombination provides the possibility for improvement of gene knockout efficiency by regulating the gene expression profiles of recombination-related genes. Transient interference with the expression of pig UBL-1/SUMO-1 and BLM is expected to improve gene targeting. The results of the present study provided important information to design siRNA knockdown vectors. They were also useful for ex ante evaluation of expression profiles of these genes in primary cultures of somatic cells, which may enhance the production of gene knockout pigs.

Molecular cloning of pig Rad51, Rad52, and Rad54 genes, which are involved in homologous recombination machinery.

BACKGROUND: The low rate of homologous recombination in somatic cells is considered to be an urgent issue. Therefore, we molecularly cloned three genes that relate to efficient homologous recombination. METHODS: Polymerase chain reaction (PCR) was performed to isolate candidate cDNA fragments from a pig spleen cDNA library with the corresponding primer sets deduced from multiple alignment analysis of other mammalian genes. A 5'- and 3'-RACE PCR experiment was performed to determine the complete cDNA sequences. RESULTS: The complete cDNA sequences of the pig RAD51, RAD52, and RAD54 genes, which are closely related to homologous recombination events, were identified using molecular cloning technique. The cDNA sequences of three genes were successfully isolated by PCR-based methods. As a result, we determined the sequences of pig RAD51 (1663 bp, 339 aa), RAD52 (1884 bp, 406 aa), and RAD54 (2884 bp, 747 aa). The nucleic acid sequence homologies of the pig RAD51, RAD52, and RAD54 genes compared with the corresponding human genes were 92.9%, 77.3%, and 90.0%; the corresponding amino acid sequence homologies were 98.8%, 71.1%, and 95.0%, respectively. CONCLUSION: The knockout of alpha-1,3-galactosyltransferase in pigs resulted in a drastic reduction in xenoantigenicity. However, other xenoantigens, in particular, the non-Gal antigens, also need to be down-regulated. Gene transfer to alter expression levels of these recombination-related molecules and/or ex ante evaluation of expression profiles of these genes in primary cultures of somatic cells constitute a new approach to enhancing homologous recombination events during the production of gene knockout pigs.

Cloning and in vitro antiapoptotic effects of pig FLIPs.

INTRODUCTION: Cellular FLICE-like protein (cFLIP) inhibits death receptor-mediated apoptosis signal transduction, such as that induced by Fas and TNFR. The present study examined the role of antiapoptotic molecules to protect pig cells from human natural killer (NK) cells in vitro, as a model of delayed-type xenograft rejection. METHODS: Pig FLIPs were cloned using the TBLASTIN program to search for cDNA fragments of pig FLIPs. The sequence was identified using the dideoxy chain termination method and an ABI PRISM3100 genetic analyzer. The cDNA of pig FLIPs was inserted into the cloning site of the chicken beta-actin promoter (pCXN2). The cDNA was then transfected into pig endothelial cells (PEC), to establish several stable PEC clones containing the cDNA. Expression of the pig FLIP gene was evaluated by reverse-transcriptase polymerase chain reaction, and NK cell-mediated cytolysis assessed, using YT cells (an NK-like cell line). RESULTS: The full-length pig FLIP encoding sequence, total 5'-region to 3'-region, was defined for the first time. PEC transfectants with the FLIP showed moderate expression of FLIPs. Transfection of PEC with plasmids encoding FLIPs inhibited NK cell-mediated PEC lysis. While approximately half of parental PEC were injured by the human NK-like YT cells, the injury rate was relatively lower in the transfectants. CONCLUSION: Overexpression of the antiapoptotic molecules, pig FLIPs, has the potential for use in protecting graft cells from human NK cells.

Investigation of cynomolgus monkey complement.

BACKGROUND: The cynomolgus monkey is one of the most popular recipient animals in xenotransplantation experiments. However, studies of the cynomolgus monkey complement are rare. In the present study, based on the study that compared the hemolytic complement titer in cynomolgus monkeys with that in humans, the complement regulatory function of human decay accelerating factor (CD55) in both human and cynomolgus monkey sera was studied. METHODS: Hemolytic complement titers in cynomolgus monkeys were calculated using the same methods as are used in humans. Next, the complement regulatory function of human DAF (CD55) in cynomolgus monkey serum was studied using porcine endothelial cells (PECs) and human DAF. RESULTS: Of the complement titers tested, such as CH50, ACH50, C4, C2, and C3, the values were relatively high, except for the C4 titer. Human DAF on the surface of PEC resulted in nearly identical complement regulatory function in the human and cynomolgus monkey sera. CONCLUSIONS: Human DAF showed nearly the same complement regulatory function in both human and cynomolgus monkey sera.

Cross-species function of the pig C1 esterase inhibitor.

BACKGROUND: The use of a bioartificial liver with pig cells for the treatment of fulminant hepatic failure will require research on the plasma complement regulatory proteins of the pig, because the liver produces most of the complement components and plasma complement regulatory proteins. In our previous study, the pig C1 esterase inhibitor (C1-INH), which functions as an inhibitor of the complement reaction in the first step of the classical pathway in the fluid phase, was cloned and some relevant features of the molecule were characterized, especially its cross-species regulation, in comparison with human C1-INH. In a further analysis, the species specificity of C1-INH was examined, using pig endothelial cells (PEC) and several types of sera. MATERIALS AND METHODS: The cDNA of pig C1-INH was used to produce the membrane type pC1-INH, pC1-INH-PI, and inserted into the cloning site of pCXN2 (chicken beta actin promoter). The pCX/pCl-INH-PI plasmid was then transfected into PEC to establish stable PEC with pCl-INH-PI. The expression of the pCl-INH-PI was evaluated by a FACS analysis, and complement-dependent cell lysis with human, dog, rabbit, and mouse sera was then assessed. RESULTS: The transfectant with pig Cl-INH-PI showed a high level of expression on PEC. The PEC transfectants showed an inhibitory effect on complement-dependent PEC lysis. Pig Cl-INH did not show the same suppressive effect for each serum. However, considering the alternative pathway activation of each serum on the pig cell membrane, it can be concluded that pCl-INH has a relatively small species restriction. CONCLUSION: Pig Cl-INH, having a similar structure to human Cl-INH, shows a strong complement regulatory function on other species sera.

Effect of FTY720 in rat small bowel transplantation: apoptosis of crypt cells and lymphocytes in gut-associated lymphoid tissues.

AIM: We investigated the extent of apoptosis in crypt cells and Peyer's patches (PPs) during small bowel allograft rejection in rats to examine the effect of FTY720 during rejection. METHODS: Orthotopic small bowel transplantations (SBTs) were performed from BN to LEW rats. Isografted animals served as controls. Three groups of SBT animals were studied on days 3, 5, and 7 after operation: isograft, untreated allograft, allograft with FTY720. FTY720 was orally administered by gavage (1 mg/kg/d) to allograft recipients on 7 consecutive days. Cryostat sections were prepared from grafts, including PPs. An in situ end-labeling (ISEL) technique was used to detect apoptotic cells. Indirect immunoperoxidase staining was also performed using monoclonal antibodies against rat Fas/Fas-L. RESULTS: Graft survival was prolonged in the FTY720-treated group. The number of ISEL-positive enterocytes in the allografts increased significantly on days 3, 5, and 7 compared with the isograft group. In the FTY720-treated group, the number of ISEL-positive enterocytes in the allografts was down-regulated significantly on days 3, 5, and 7 compared with untreated allograft group. In the PPs, the number of ISEL-positive mononuclear cells increased significantly in the allografts compared with the isograft group. In the FTY720-treated groups, the number of ISEL-positive mononuclear cells were down-regulated significantly in the allografts compared with the untreated allograft group. The number of Fas/FasL-positive enterocytes were increased significantly in allografts compared with isograft group. In FTY720-treated groups, the number of Fas/FasL-positive enterocytes were down-regulated significantly on day 7 compared with the untreated allograft group. In the PPs, Fas/FasL-positive mononuclear cells also increased significantly on day 7 in the allografts compared with isografts. In the FTY720-treated groups, Fas/FasL-positive mononuclear cells were down-regulated significantly in the allografts compared with the untreated allograft group. CONCLUSIONS: The number of apoptotic enterocytes, lymphocytes, and Fas/FasL-positive lymphocytes increased during small bowel graft rejection. FTY720 prevented up-regulation of the number of apoptotic enterocytes, lymphocytes, and Fas/FasL-positive lymphocytes while also prolonging small bowel allograft survival.

The effect of human command phonetic characteristics on auditory cognition in dogs (Canis familiaris).

Six dogs (Canis familiaris) were trained to sit and come reliably in response to tape-recorded commands. The phonemes within these commands were then changed, and the dogs' behavior in response to these modified commands was recorded. Performance markedly declined in all cases, with the type of alteration affecting response to the modified sit command but not to the modified come command. The results suggest that dogs do not perceive a tape-recorded command as simply a physical sound but that they recognize a relationship between certain sounds.

Effect of FTY720 in rat small bowel transplantation: expression of mucosal addressin cell adhesion molecule-1.

AIM: Mucosal addressin cell adhesion molecule-1 (MAdCAM-1) mediates the homing of lymphocytes to gut-associated tissues (GALT). We performed a semiquantitative analysis of MAdCAM-1 expression during small bowel graft rejection in rat treated with FTY720. METHODS: Orthotopic small bowel transplantations (SBT) were performed from BN rats to LEW rats. Isografted animals served as controls. Three groups of SBT animals were studied on days 3, 5, 7 after operations (Isograft, untreated allograft, allograft with FTY720). FTY720 was orally administered by gavage (1 mg/kg/d) to allograft models on 7 consecutive days. Cryostat sections were prepared from grafts, including Peyer's patches (PPs). Indirect immunoperoxidase staining was performed using mAbs against MAdCAM-1. The degree of vascular endothelial staining on high endothelial venules (HEV) in the PPs was graded from 1 (low levels) to 5 (high levels), and in the vessels of the lamina propia from 1 (faint), to 2 (low at the base of villi), 3 (low to the middle of villi), 4 (high to the middle of villi), to 5 (high to villi tip). RESULTS: The graft survival was prolonged in the FTY720-treated group. MAdCAM-1 expression on HEVs in PPs was down-regulated during rejection. In contrast its expression on endothelial cells of vessels in the lamina propria was up-regulated during rejection. In the FTY720-treated groups, MAdCAM-1 expression on HEVs in PPs was up-regulated and its expression on endothelial cells of vessels in the lamina propria was down-regulated compared with untreated allograft group. CONCLUSIONS: Alteration in MAdCAM-1 expression may be associated with the development of SB graft rejection. The vessels at the base of villi, which are associated with lymphocyte recruitment, may become sites of intestine immune reactivity during the early phase of small bowel allograft rejection. FTY720 was found to prevent the down-regulation of MAdCAM-1 expression on HEVs in PPs and the up-regulation of its expression on endothelial cells of vessels in the lamina propria while also prolonging small bowel allograft survival.

Semiquantative analysis of expression of mucosal addressin cell adhesion molecule-1 during small bowel graft rejection in rats.

AIM: Mucosal addressin cell adhesion molecule-1 (MAdCAM-1) mediates the homing of lymphocytes to gut-associated lymphoid tissues (GALT). We performed a semiquantative analysis of MAdCAM-1 expression during small bowel graft rejection. METHODS: Orthotopic small bowel transplantations (SBT) were performed from BN rats to LEW rats. Isografted animals served as controls. Animals were sacrificed on days 3, 4, 5, 6, and 7 after SBT. Cryostat sections were prepared from grafts, including Peyer's patches (PPs). Indirect immunoperoxidase staining was performed using mAbs against MAdCAM-1. The degree of vascular endothelial staining on high endothelial venules (HEV) in the PPs was graded from 1 (low levels) to 5 (high levels), and in the vessels of the lamina propria from 1 (faint), 2 (low at the base of villi), 3 (low to the middle of villi), 4 (high to the middle of villi), to 5 (high to villus tip). RESULTS: MAdCAM-1 expression on HEVs in PPs was down-regulated during rejection. In contrast its expression on endothelial cells of vessels in the lamina propria was up-regulated during rejection. CONCLUSION: Alteration in MAdCAM-1 expression may be associated with the development of SB graft rejection. The vessels at the base of villi, which are associated with lymphocyte recruitment, may become sites of intense immune reactivity during the early phase of small bowel allograft rejection.

Apoptosis of crypt cells and lymphocytes in gut-associated lymphoid tissues during small intestinal graft rejection in rats.

INTRODUCTION: We investigated the extent of apoptosis in crypt cells and Peyer's patches (PPs) during small bowel allograft rejection in rats to examine whether the Fas/FasL pathway participates in apoptosis within grafts during rejection. MATERIALS AND METHODS: Orthotopic small bowel transplantation with portocaval drainage was performed from Brown Norway to Lewis (LEW) rats. Isografted (LEW --> LEW) and nontransplanted animals served as the controls. Animals were sacrificed on days 3, 5, on 7 after SBT (each n = 5). An in situ end-labeling (ISEL) technique was used to detect apoptotic cells. Indirect immunoperoxidase staining was also performed using monoclonal antibodies against rat Fas or Fas-L. RESULTS: The number of ISEL-positive enterocytes in the allografts increased significantly on days 3, 5, and 7. Similarly, in the PPs of the allografts, the number of ISEL-positive mononuclear cells increased significantly on days 3, 5, and 7. On day 7 the number of Fas- and FasL-positive enterocytes were increased significantly in the allografts compared with the nontransplanted controls. Similarly, in the PPs, Fas- and FasL-positive mononuclear cells also increased significantly on day 7 in the allograft. CONCLUSION: Although an increase, number of apoptotic enterocytes and lymphocytes were observed in the early phase, activation of Fas/FasL system occurred during the late phase of small bowel graft rejection. These findings suggest that both rejection-associated and sepsis-induced forms of apoptosis may be associated with small bowel graft rejection.

Expression of mucosal addressin cell adhesion molecule-1 (MAdCAM-1) during small-bowel graft rejection in rats.

BACKGROUND: Mucosal addressin cell adhesion molecule-1 (MAdCAM-1) is a critical endothelial adhesion molecule for lymphocyte trafficking to gut-associated lymphoid tissues (GALT) under physiological conditions. It is expressed on special postcapillary venules, that is the high endothelial venules (HEV) in GALT. In this study, we investigated changes in MAdCAM-1 expression during small-bowel graft rejection. METHODS: Orthotopic small-bowel transplantation (SBT) with portocaval drainage was performed from brown Norway (BN) rats to Lewis (LEW) rats. Isografted (LEW --> LEW) and untransplanted animals served as controls. Animals were killed on days 3, 4, 5, 6 and 7 after SBT. Cryostat sections (6 microm thick) were prepared from normal small-bowel tissues and small-bowel grafts, including Peyer patches (PPs). Indirect immunoperoxidase staining was performed using monoclonal antibodies (mAbs) against rat MAdCAM-1 (OST12). RESULTS: In the PPs of controls, MAdCAM-1 antibodies specifically stained the endothelial cells of HEV, which were predominantly located in the interfollicular areas. In the allografts on day 4 after SBT, the MAdCAM-1 expression was weaker on the HEV in the PPs than in the controls. In the lamina propria of controls, a faint expression of MAdCAM-1 on vessels was observed. On day 4 after allogeneic SBT, the MAdCAM-1 was more strongly expressed on the endothelial cells of the vessels at the base of the villi. As rejection developed, the MAdCAM-1 expression on the vessels progressed toward the villus tip. CONCLUSIONS: The change of MAdCAM-1 expression may be involved in the development of small-bowel graft rejection. The vessels at the base of villi, which is associated with lymphocyte recruitment, may become a site of intense immune reactivity in the early phase of small-bowel allograft rejection.