Heterotopic Transplantation Research Articles

Establishment of a patient-derived Wilms' tumor xenograft model: A promising tool for individualized cancer therapy

ObjectiveLack of appropriate approaches that reliably predict response of Wilms' tumor (WT) to anticancer agents remains a major deficiency in clinical practice of individualized cancer therapy. The aim of this study was to establish a patient-derived tumor tissue (PDTT) xenograft model of WT for individualized chemotherapeutic regimen selection in accordance with the patient's tumor nature. Material and methodsTumor specimens of a primary WT were orthotopically implanted into three nude mice, and after 4 weeks xenografts were harvested for serial heterotopic transplantation in 20 nude mice that were divided into three experimental groups and one control group. In vitro and in vivo chemosensitivity to doxorubicin, actinomycin-D, and vincristine were evaluated. Hematoxylin and eosin (H&E) staining and immunohistochemical examination with desmin, vimentin, myogenin, and neuron-specific enolase (NSE) were also applied to determine histological stability of the xenograft during serial transplantation compared with the original tumor tissue. ResultsThe xenograft model was successfully established. Histopathologic characteristics of the xenograft tumors were similar to the patient's tumor. Early passage of the PDTT showed a similar chemosensitivity pattern to the original tumor tissue. ConclusionsPDTT xenograft of WT provides an appropriate model for individualized cancer therapeutic regimen selection by means of its biological stability compared with original patient's tumor.

GW24-e3067 Animal model for unloading the rat hearts of end-stage dilated cardiomyopathy

ObjectivesTo create a model of minicking VAD by unloading rats with HF (heart failure) after dilated cardiomyopathy in rats.MethodsHeart failure (HF) was induced by the intraperitoneal administration of doxorubicin (total...

IL-17A Mediates Early Post-Transplant Lesions after Heterotopic Trachea Allotransplantation in Mice

Primary graft dysfunction (PGD) and bronchiolitis obliterans (BO) are the leading causes of morbidity and mortality after lung transplantation. Reports from clinical and rodent models suggest the implication of IL-17A in either PGD or BO. We took advantage of the heterotopic trachea transplantation model in mice to study the direct role of IL-17A in post-transplant airway lesions. Across full MHC barrier, early lesions were controlled in IL-17A-/- or anti-IL17 treated recipients. In contrast, IL-17A deficiency did not prevent subsequent obliterative airway disease (OAD). Interestingly, this early protection occurred also in syngeneic grafts and was accompanied by a decrease in cellular stress, as attested by lower HSP70 mRNA levels, suggesting the involvement of IL-17A in ischemia-reperfusion injury (IRI). Furthermore, persistence of multipotent CK14+ epithelial stem cells underlined allograft protection afforded by IL-17A deficiency or neutralisation. Recipient-derived γδ+ and CD4+ T cells were the major source of IL-17A. However, lesions still occurred in the absence of each subset, suggesting a high redundancy between the innate and adaptive IL-17A producing cells. Notably, a double depletion significantly diminished lesions. In conclusion, this work implicated IL-17A as mediator of early post-transplant airway lesions and could be considered as a potential therapeutic target in clinical transplantation.

Short-Course Rapamycin Treatment Preserves Airway Epithelium and Protects Against Bronchiolitis Obliterans

Damage to airway epithelium is closely related to the development of bronchiolitis obliterans (BO) in pulmonary transplantation. Rapamycin protects against BO development in a murine model, but its use in patients undergoing lung transplantation is limited by its side effects. We hypothesized that short-course rapamycin dosing could be used to prevent airway epithelium loss and protect against BO development in a murine model. A total alloantigenic mismatch, murine, heterotopic tracheal transplant model of BO was used. Animals were treated with either rapamycin or dimethyl sulfoxide (controls) according to one of three treatment regimens: (1) days 1 through 14 after transplantation, (2) days 3 through 7 after transplantation, or (3) days 14 through 28 after transplantation. Epithelial loss was assessed by use of hematoxylin and eosin stains 14 and 28 days after transplantation. Tracheal luminal obliteration was assessed at 28 days. Early rapamycin treatment was protective against epithelial loss 14 days after transplantation in comparison with control animals (p < 0.001). Rapamycin treatment from days 1 to 14 was more effective at epithelial preservation (p = 0.002) and reducing luminal obliteration (p < 0.001) at 28 days than was rapamycin treatment from days 3 to 7. Late rapamycin treatment (days 14 to 28) allowed for recovery of the previously denuded epithelium at 28 days (92.5% epithelial loss to 35.6%) and a reduction in BO (p < 0.001). Short-course rapamycin treatment protects against airway epithelium loss and subsequent development of BO in a murine model. Because of its immunosuppressive and antifibrotic effects, rapamycin may prove to be the ideal medication to prevent chronic rejection and BO in patients undergoing lung transplantation.

Gene Expression Changes in Rat Pancreas Transplant Model After Long-Term Cold Storage of the Graft in Perfluorohexyloctane

BackgroundPerfluorohexyloctane (PFH) is a promising storage solution that has been successfully used for pancreas preservation before islet isolation. This hyperoxygen carrier has been designed to prevent ischemic injury to the pancreas graft during cold storage. In our storage, we aimed to evaluate the impact of this solution on long-term cold storage in a rat whole pancreas transplantation model. MethodBrown-Norway rats were used for syngeneic heterotopic pancreas transplantation. The procured organs were cold-stored for 18 hours in preoxygenated PFH (PFH group; n = 8) or in the University of Wisconsin solution (UW group; n = 8), or were transplanted immediately in the control group (n = 8). Two hours after reperfusion, we obtained blood and pancreas tissue samples for biochemistry and gene analyses (real-time polymerase chain reaction). ResultsA significant difference between the UW and PFH group was observed in the tumor necrosis factor (TNF)β and endothelin 1 genes, which was overexpressed more than twofold in the UW group. In the blood samples, the UW group compared with the PFH group showed significantly higher levels of pancreatic amylase and lipase (94.2 ± 25.2 vs 67.7 ± 13.4 μkat/L and 5.5 ± 2.8 vs 3 ± 0.7 μkat/L, respectively; P < .05). ConclusionWe found significantly lower expression levels of the endothelin 1 and TNFβ genes and lower concentrations of pancreatic amylase and lipase in the PFH group. All these findings suggest lower rate of ischemic reperfusion injury in the PFH group. These findings may result in better post-transplant outcomes after long-term cold storage in PFH compared with the UW solution. Further research in this area is required.

Small Animal Models of Experimental Obliterative Bronchiolitis

Despite significant progress in the treatment of chronic lung allograft rejection, obliterative bronchiolitis (OB) remains the major limitation to long-term survival after lung transplantation. The use of animal models is critical to an understanding of the pathological mechanisms behind OB, and to develop therapeutic strategies for OB. For almost 20 years, the technique of heterotopic tracheal transplantation was the leading experimental model in OB research. To address the need for a more physiologic experimental setup, a variety of small animal models have been proposed during the past two decades, such as the orthotopic tracheal transplantation model or the intrapulmonary trachea implantation model. The recent introduction of the orthotopic lung transplantation model in the mouse fulfilled the criteria for a physiologic lung transplantation setup, and also presents the advantage of being genetically modifiable. Here we review the evolution of OB models and their applications, from their beginning to the rapidly emerging physiologic models of chronic lung allograft rejection.

Experimental study of the impact of hyperlipidemia on the chemotherapy in colorectal cancer model

To study the effect of hyperlipidemia on the prognosis and therapeutic response for colorectal cancer and to explore the associated mechanism. The hyperlipidemic subcutaneous heterotopic colorectal cancer orthotopic transplant model of nude mice was established by feeding high fat diet and performing transplantation. Seventy mice were divided into 7 groups with 10 mice in each group. Two groups were used as pre-experiment. The remaining 5 groups included 4 high-fat groups (G1 to G4), and 1 normal-diet control group (G5). G1, G2, G3, G4, and G5 received normal saline, capecitabine, simvastatin, capecitabine plus simvastatin and capecitabine respectively for 3 weeks. Changes of tumor volume, tumor weight, tumor growth rate and blood lipid parameters (TC, TG, HDL, LDL, Lpa, apoA and apoB) were observed. In G1 to G4, TC, HDL, apoA, TG, LDL, Lpa, apoB increased, but only TC, HDL, apoA were significantly different as compared with G5 (P=0.020, P=0.001, P=0.001, P=0.911, P=0.249, P=0.681, P=0.053). The tumor in G1 grew fastest, and its growth rate was significantly different as compared with G2, G4, G5 except G3 (P=0.001, P=0.806, P=0.001, P=0.010). The tumor growth rate of G3 was lower than group G1, but higher than G2, G4, G5 with significant difference (P=0.001, P=0.002, P=0.016). The tumor of G5 grew faster than G2 and G4, but without significant differences (P=0.051, P=0.070). The tumor of G4 grew slowest without significant difference as compared to G2 (P=0.438). Compared with pre-administration, at the third week, the TC of G1 was increased [(3.8±0.4) mmol/L], while the other 4 groups decreased [G2 (2.8±1.8) mmol/L, G3 (2.9±0.7) mmol/L, G4 (1.4±0.9) mmol/L, G5 (2.1±0.2) mmol/L]. G4 decreased significantly (P=0.004). At the fifth week, the TC of all the 5 groups decreased, while the lipids of G4 were higher as compared to those at the third week. The TG, Lpa, ApoA were significantly decreased at the third week (all P<0.05), while no significant differences were found in HDL and apoB. A hyperlipidemia colon tumor model involving subcutaneous colon translocation and orthotopic transplantation of nude mice is successfully established. This model is an ideal research model for hyperlipidemia and colorectal cancer. The effect of capecitabine on tumors in hyperlipidemia groups is better as compared to normal diet group. The proliferation of tumor cells can increase serum total serum cholesterol.

Evidence for a common progenitor of epithelial and mesenchymal components of the liver

Tissues of the adult organism maintain the homeostasis and respond to injury by means of progenitor/stem cell compartments capable to give rise to appropriate progeny. In organs composed by histotypes of different embryological origins (e.g. the liver), the tissue turnover may in theory involve different stem/precursor cells able to respond coordinately to physiological or pathological stimuli. In the liver, a progenitor cell compartment, giving rise to hepatocytes and cholangiocytes, can be activated by chronic injury inhibiting hepatocyte proliferation. The precursor compartment guaranteeing turnover of hepatic stellate cells (HSCs) (perisinusoidal cells implicated with the origin of the liver fibrosis) in adult organ is yet unveiled. We show here that epithelial and mesenchymal liver cells (hepatocytes and HSCs) may arise from a common progenitor. Sca+ murine progenitor cells were found to coexpress markers of epithelial and mesenchymal lineages and to give rise, within few generations, to cells that segregate the lineage-specific markers into two distinct subpopulations. Notably, these progenitor cells, clonally derived, when transplanted in healthy livers, were found to generate epithelial and mesenchymal liver-specific derivatives (i.e. hepatocytes and HSCs) properly integrated in the liver architecture. These evidences suggest the existence of a 'bona fide' organ-specific meso-endodermal precursor cell, thus profoundly modifying current models of adult progenitor commitment believed, so far, to be lineage-restricted. Heterotopic transplantations, which confirm the dual differentiation potentiality of those cells, indicates as tissue local cues are necessary to drive a full hepatic differentiation. These data provide first evidences for an adult stem/precursor cell capable to differentiate in both parenchymal and non-parenchymal organ-specific components and candidate the liver as the instructive site for the reservoir compartment of HSC precursors as yet non-localized in the adult.

Establishment of animal model for unloading the infarcted rat hearts

Objective To create a model of minicking ventricular assist device (VAD) by unloading rats with heart failure (HF) after ischemic cardiomyopathy in rats.Methods HF models after ischemic cardiomyopathy were established in 29 adult Lewis rats by ligating the middle-distal 1/3 segment of left anterior descending artery.Rats with HF after coronary artery ligation were unloaded by heterotopic cardiac transplantation for 2 weeks.Results The successful rate for establishment of HF model after ischemic cardiomyopathy was 82.76％ (24/29).The successful rate of the unloading rate in rats with HF after coronary artery ligation was 71.43％ (20/24).As compared with control group,left ventricle end-diastolic pressure (LVEDP) and the maximum pressure rise and fall velocity(± dp/dtmax) were increased significantly in unloading group (P ＜ 0.05).Conclusion We establish a model mimicking partially the left VAD.The infarcted cardiac function could be improved by unloading. Key words: Models, animals; Myocardial infarction; Left Venticular assist device; Heart failure ; Rats

Protective effects of N-acetylcysteine on myocardial ischemia-reperfusion injury in the rat heart transplantation

Objective To explore the protective effect of N-acetylcysteine (NAC) on graft ischemia-reperfusion injury (IRI) in the rat heart transplantation.Methods 100 healthv male Lewis rats and 20 healthy male BN rats were randomly divided into four groups.In control group,2 ml normal saline was infused via the inferior vena cave 30 min before donor harvest or implantation.In donor preconditioning group,NAC (300 mg/kg body weight,iv.) was infused via the inferior vena cave 30 min before donor harvest,and the recipient was not processed.In recipient preconditioning group,NAC (300 mg/kg body weight,iv.) was infused via the inferior vena cava 30 min before recipient implantation,and the donor was not processed; Grafts underwent cold storage in 4℃ conventional histidine-tryptophan-ketoglutarate(HTK)solution for 18 h prior to heterotopic transplantation (Lewis→Lewis).Another 20 male Lewis rats for recipients,and 20 male BN rats for donors were used for survival analysis.Graft function was monitored by daily palpation.Blood was drawn at 6 and 24 h post-reperfusion for analysis of creatine kinase isoenzvme MB (CK-MB),Troponin T (TnT),lactic acid dehydrogenase (LIDH) as markers of graft injury.Graft superoxide dismutase (SOD),and lipid hydroperoxide (LPO) activity were detected at 24 h after reperfusion.Tissue samples were taken 24 h after reperfusion for histological and ultrastructural changes.Inducible nitric oxide svnthase (iNOS) and endothelial nitric oxide syuthase (eNOS) protein expression was detected by using immunohistochemistrv.The expression of iNOS and eNOS mRNA was detected using by real-time quantitative polymerase chain reaction (Real-time PCR).Results Suaival rate of rats in the NAC pretreatment groups was significantly higher than in control group.The serum levels of CK-MB,TnT,LIDH at 6/24 h after reperfusion were reduced significantly in donor preconditioning group or recipient preconditioning group as compared with control group [for CK-MB,(10 681.11 ± 2052.01)/(12 903.29 ± 1789.46)/(31093.11 ± 6822.67) U/L at 6 h,and (1797.89 ± 383.96)/(3408.0 ± 1028.48)/(2230.40 ±450.03) U/Lat24h; forTnT,(45.76±7.46)/(17.90±2.87)/(49.51 ±6.41) μg/L at 6 h,and(11.08±1.53)/(7.06 ±0.71)/(20.28 ±2.90) μg/L at 24 h; for LDH,(4019.00 ±678.03)/(4235.17 ±585.88)/(8197.00 ±807.20) U/L at 6 h,and (1005.67 ± 164.71)/(774.00 ± 113.13)/(1619.50 ± 289.11) U/L at 24 h],respectively.LPO activity at 24 h after reperfusion was lower (9.48 ± 1.05)/(7.82 ± 1.56) vs.(10.90 ±2.28) μmol/L,and SOD activity was significautly higher in pretreatment groups (4.71 ± 1.09)/(4.57 ± 1.09) vs.(2.38 ±0.39) U/ml than in control group (P ＜0.05).Histological examinations (HE staining and electron microscopy) also proved that the injury in pretreatment group was alleviated as compared with control group.Immunohistochemical analysis and Real-time PCR revealed the decreases of iNOS (1.50 ± 0.22)/(1.63 ± 0.26) vs.(3.00 ± 0.15) and (0.95 ± 0.41) / (0.43 ± 0.17) vs.(1.00 ± 0.41),and the increase of eNOS (3.60 ± 0.16) / (3.40 ± 0.26) vs.(2.00 ± 0.21) and (3.06 ± 1.47)/(1.48 ± 0.53) vs.(1.00 ± 0.65) in pretreatment group as compared with control group.Conclusion NAC reduces IRI after heart transplantation and improves the outcome of the transplanted heart after prolonged cold preservation,which is most likely through anti-oxidation and enhancing the oxidase activity to reduce myocardial cell injury,thereby reducing mvocardial IRI. Key words: N-acetylcysteine; Heart transplation; Ischemia reperfusion injury

Inhibition of accelerated rejection mediated by alloreactive CD4+ memory T cells and prolonged allograft survival by arsenic trioxide

The aim of this study was to evaluate and determine the potential mechanisms of As2O3 in accelerated rejection mediated by alloreactive CD4+ memory T cells. Vascularized heterotopic cardiac transplantation from C57BL/6 mice to nude mice (pre-transferred CD4+ memory T cells) was performed on Day 0, and As2O3 was administered to recipient mice from Day 0 to 10. As a result, As2O3 could reduce the proliferation of allo-primed CD4+ memory T cells in vitro in MLR and the baseline rate of proliferation was restored by the addition of exogenous IL-2. In vivo, compared with the control[+] group, the mean survival time of cardiac allografts in the As2O3 group was prolonged from 5.8 ± 0.7 to 14.2 ± 2.5 days. Five days after transplantation, the relative gene expression of IL-2, IFN-γ and Foxp3 was reduced in the grafts by As2O3 treatment, but the expression of IL-10 and TGF-β was increased. Correspondingly, the proportions of CD4+ T cells, CD4+ memory T cells and regulatory T cells (Tregs), both in recipient spleens and lymph nodes, were lowered. These results indicate the potential of As2O3 as a novel immunosuppressant targeting CD4+ memory T cells.

Occipital somites guide motor axons of the accessory nerve in the avian embryo

The accessory nerve (nervus accessorius) displays a unique organization in that its axons ascend along the rostrocaudal axis after exiting the cervical spinal cord and medulla oblongata and thereafter project ventrally into the periphery at the first somite level. Little is known about how this organization is achieved. We have investigated the role of somites in the guidance of motor axons of the accessory nerve using heterotopic transplantations of somites in avian embryos. The formation of not only accessory nerve but also the vagal nerve was affected, when a more caudal occipital somite (somites 2–4) was grafted to the position of the first occipital somite. Our study reveals that only the first occipital somite permits the development of ventral projection of accessory axons, a process that is inhibited by more caudal occipital somites.

Function and Expression of Cystic Fibrosis Transmembrane Conductance Regulator after Small Intestinal Transplantation in Mice

The secretion function of intestinal graft is one of the most important factors for successful intestinal transplantation. Cystic fibrosis transmembrane conductance regulator (CFTR) mediates HCO3 - and Cl- secretions in intestinal epithelial cells. In this study, we made investigation on the expression and function of CFTR in an experimental model of murine small intestinal transplantation. Heterotopic intestinal transplantations were performed in syngeneic mice. The mRNA and protein expressions of CFTR were analyzed by real time PCR and western blot. Murine intestinal mucosal HCO3 - and Cl- secretions were examined in vitro in Ussing chambers by the pH stat and short circuit current (Isc) techniques. The results showed that forskolin, an activator of CFTR, stimulated jejunal mucosal epithelial HCO3 - and Cl- secretions in mice, but forskolin-stimulated HCO3 - and Cl- secretions in donor and recipient jejunal mucosae of mice after heterotopic jejunal transplantation were markedly decreased, compared with controls (P<0.001). The mRNA and protein expression levels of CFTR in donor and recipient jejunal mucosae of mice were also markedly lower than those in controls (P<0.001), and the mRNA and protein expression levels of tumor necrosis factor α (TNFα) were markedly increased in donor jejunal mucosae of mice (P<0.001), compared with controls. Further experiments showed that TNFα down-regulated the expression of CFTR mRNA in murine jejunal mucosa. In conclusion, after intestinal transplantation, the function of CFTR was impaired, and its mRNA and protein expressions were down-regulated, which may be induced by TNFα.

Orthotopic and heterotopic tracheal transplantation model in studying obliterative bronchiolitis

BackgroundSeveral animal models have been established to investigate the mechanisms of obliterative bronchiolitis after lung transplantation. In this study, we compared three prevalent murine models of obliterative bronchiolitis in terms of several basic pathologic changes in a relatively short span of time after transplantation. MethodsEach of the recipient mice simultaneously received orthotopic, intra-omental and subcutaneous tracheal transplantation in both syngeneic and allogeneic settings. No immunosuppressive treatment was administered. Tracheal grafts were harvested on Day 14, 21 and 28 after transplantation for histological and immunohistochemical analyses. ResultsSyngeneic tracheal grafts from different transplant sites retained normal histologic structures, while their corresponding allografts demonstrated more occlusion of the airway lumen as well as more infiltration of CD4+/CD8+ mononuclear cells and myofibroblasts, but less regenerative epithelium and neovascularized vessels at indicated times (P<0.05). Compared with two heterotopic allografts, orthotopic allografts had less occlusion of the tracheal lumen as well as less infiltration of CD4+/CD8+ mononuclear cells and myofibroblasts, but more regenerative epithelium and neovascularized vessels (P<0.05). ConclusionsOrthotopic tracheal transplantation in mice can be considered as a model to study early stages of obliterative bronchiolitis, and heterotopic tracheal transplantation can be a model for late stages of obliterative bronchiolitis.

Rapamycin Blocks Fibrocyte Migration and Attenuates Bronchiolitis Obliterans in a Murine Model

Fibrocytes are integral in the development of fibroproliferative disease. The CXCL12/CXCR4 chemokine axis has been shown to play a central role in fibrocyte migration and the development of bronchiolitis obliterans (BO) after lung transplantation. Inhibition of the mammalian target of rapamycin (mTOR) pathway with rapamycin has been shown to decrease expression of both CXCR4 and its receptor agonist CXCL12. Thus, we hypothesized that rapamycin treatment would decrease fibrocyte trafficking into tracheal allografts and prevent BO. A total alloantigenic mismatch murine heterotopic tracheal transplant (HTT) model of BO was used. Animals were either treated with rapamycin or dimethyl sulfoxide (DMSO) for 14 days after tracheal transplantation. Fibrocyte levels were assessed by flow cytometry, and allograft neutrophil, CD3(+) T-cell, macrophage, and smooth muscle actin (SMA) levels were assessed by immunohistochemistry. Tracheal luminal obliteration was assessed on hematoxylin and eosin (H&E) stains. Compared with DMSO-treated controls, rapamycin-treated mice showed a significant decrease in fibrocyte levels in tracheal allografts. Fibrocyte levels in recipient blood showed a similar pattern, although it was not statistically significant. Furthermore, animals treated with rapamycin showed a significant decrease in tracheal allograft luminal obliteration compared with controls. Based on immunohistochemical analyses, populations of α-SMA-positive (α-SMA(+)) cells, neutrophils, CD3(+) T cells, and macrophages were all decreased in rapamycin-treated allografts versus DMSO controls. Rapamycin effectively reduces recruitment of fibrocytes into tracheal allografts and mitigates development of tracheal luminal fibrosis. Further studies are needed to determine the cellular and molecular mechanisms that mediate the protective effect of rapamycin against BO.

ASSA13-13-10 Establishment of Animal Model For Unloading the Infarcted Rat Hearts

<h3>Objective</h3> To create a model of minicking VAD by unloading rats with HF (heart failure) after ischemic cardiomyopathy in rats. <h3>Methods</h3> Heart failure (HF) after ischemic cardiomyopathy was established in 29 adult lewis rats by ligating the middle-distal 1/3 segment of left anterior discending artery. Rats with HF after coronary artery ligation were unloaded by heterotopic cardiac transplantation for 2 weeks. <h3>Results</h3> The rate of heart failure after ischemic cardiomyopathy successfully was 82.76% (24/29). The rate of the unloading the rats with HF after coronary artery ligation successfully was 71.43% (20/24). The cardiac function indicated by LVEDP and ± dp/dtmax increased. <h3>Conclusions</h3> We established a model mimicking partially the Left Venticular assist Device (LVAD). The infarcted cardiac function could be improved by unloading.

β-Catenin Activation in Bronchiolitis Obliterans Syndrome

Purpose β-catenin, an integral cell-cell adhesion adaptor protein and a transcriptional co-regulator, has recently been shown to be important in promoting mesenchymal cell activation. BOS is a fibrotic disease of the small airways with BO lesions demonstrating myofibroblast infiltration and collagen deposition as prominent features. In this study we investigate β-catenin activation in human BOS as well as animal BO model. Methods and Materials Whole cell lysate and nuclear cell fraction from mesenchymal stromal cells derived from patients with and without BOS were collected and analyzed by western blot for β-catenin activation. Immunofluorescence and immunohistochemical staining were done on human cells and fibrotic biopsy tissue from patients with BOS. Heterotopic tracheal transplant model was used to test for β-catenin activation at different time points. Results Up regulation of total and nuclear β-catenin expression was noted in mesenchymal cells from patients with BOS. In vitro, β-catenin staining demonstrated positive nuclear localization in BOS cells. In vivo activation was confirmed by the positive nuclear β-catenin staining in myofibroblasts in human biopsy tissue from BOS patients. In heterotopic tracheal transplant model animal model, a significant increase in β-catenin mRNA expression was noted in allografts at day 7 after tracheal transplantation. Investigation of protein expression in tracheal grafts demonstrated a significantly β-catenin in allografts by day 14 as compared to isografts. β-catenin staining by immunohistochemical staining was studied at day 21, a time point by which complete luminal obliteration by mesenchymal cells is noted. Allografts demonstrated intense cytoplasmic and nuclear β-catenin staining in the infiltrating cells in the lumen. In isografts, β-catenin staining was noted in the membranous pattern in the epithelial cells with no significant nuclear staining. Conclusions This is the first investigation of β-catenin activation in BOS and suggests an important role for this pathway in the fibrogenesis in allografts.

Overexpression of IL-1 Receptor Antagonist Attenuates Obliterative Bronchiolitis in Murine Tracheal Transplant Model

Purpose Obliterative bronchiolitis (OB) remains an impediment to long-term survival after lung transplantation. IL-1 beta (IL-1β) has been studied as proinflammatory and profibrotic factor in allograft chronic lung tissue rejection. IL-1 receptor antagonist (IL-1rn) is competitive inhibitor to IL-1β and mediates the anti-inflammatory and antifibrotic effects of mesenchymal stem cells during lung injury. We hypothesized that IL-1rn overexpression prevents the progression of OB in an established heterotopic tracheal transplantation model. Methods and Materials Tracheas from BALB/c mice were implanted and wrapped in the omentum of BALB/c (isografts), C57BL/6 (allografts), IL-1rn overexpression (IL-1rn+/+), IL-1rn knock out (IL-1rn-/-) mice. The tracheas explanted after 21 days were evaluated histologically, and real time-PCR for IL-1rn, IL-1β, IL-1 alpha (IL-1α) mRNA levels. Cytokine quantification for these proteins in plasma samples was done by ELISA 21 days after surgery. Results IL-1rn overexpression mice showed significant reduction of the tracheal luminal occlusion compared to control allograft animals (p figure 1 ] There was also significant increase in plasma IL-1rn levels in the IL-1rn +/+ animals as compared to other groups (p Conclusions The results suggest that IL-1rn overexpression protects against experimental OB. These findings provide new insights into the mechanisms of lung chronic rejection and may lead to new strategy for the treatment of OB.

Four Decades of Vascularized Heterotopic Cardiac Transplantation in the Mouse

ABSTRACTSince the first clinical heart transplant in 1967, there has been a heightened need to understand immune and inflammatory responses to “foreign” tissues. Research efforts in those early days were based on species that would now be considered “large” and were typically out-bred individuals. While this closely mirrors the clinical scenario, where genetic mismatches of donors and recipients can only be minimized in the selection process, these were not ideal models for studying the complexities and nuances of the immune system. Even when the rat was considered the standard model those early endeavors were limited by a small number of rat strains. The mouse model has provided us with an overwhelming array of strains, knockouts, knockins and transgenics that allow us to investigate the many layers of the innate and adaptive immune systems leading to a much greater understanding of immune responses. Fully vascularized heterotopic cardiac transplantation in the mouse has now been with us for four decades; the original papers describing this technique being published by Corry in 1973. In the subsequent 40 years, this technique has been used by many laboratories, including our own, and has become a powerful tool for the investigation of transplant immunity and ischemia reperfusion injury. Given the modern availability of mouse strains and mouse-related reagents, our current understanding of transplant immunity undoubtedly would not exist without such a technique.

Динаміка морфогенезу і функціонального розвитку алотрансплантата оваріальної тканини щурів

We examined the dynamics of folliculogenesis in ovarian tissue allograft and its endocrine function in an organism of castrated recipient rats during 100 days. Growth and development of ovarian tissue and its steroidogenic function in heterotopic transplantation were determined by its initial morphological organization. Allotransplantation of mature ovarian tissue was found to cause preservation of its morphological structure, whereas the transplantation of neonatal ovarian tissue caused formation of follicular cysts. At 100th day of observation, we observed a recovery of the levels of sex hormones to the physiological norm after transplantation of both mature ovarian tissue and neonatal tissue of 10-days of postnatal development.