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Objective To explore the role of MyD88 in heterotopic tracheal transplantation in mice and its relationship with histopathological changes.Methods The mouse model of hetemtopictracheal transplantation was used.The mice were divided into three groups:(1) tracheal isograft of C57BL/6 to C57BL/6 mice;(2) tracheal allograft of BALB/c to C57BL/6 mice;(3) tracheal graft of BALB/c to C57BL/6 mice with MyD88 inhibitor treatment.The tracheal grafts were collected at indicated time points.Histological sections were stained with hematoxylin and eosin.The pathological changes were observed and their semi-quantitative measurement was done with Image J software.Results (1) Pathological results showed that the structure of the trachea with MyD88 inhibitor treatment was clear and the loss of epithelial cells was significantly reduced as compared with the positive control group at the time of 7 and 14 days.(2) The results of semi-quantitative measurement showed that luminal occlusion rate of MyD88 inhibitor treatment group was significantly reduced as compared with the positive control group (P＜0.01).However,the loss of epithelial cells was not improved 7 days after transplantation.Both of lumen occlusion rate (P＜0.05) and epithelial cells loss (P＜0.01) in MyD88 inhibitor treatment group were significantly reduced.Conclusion Inhibition of MyD88 molecule could significantly alleviate pathological changes of the transplanted trachea.Both of luminal occlusion rate and loss of epithelial cells were significantly ameliorated.
ABSTRACT
Long-segment tracheal defects are difficult to be managed by conventional surgical means,which often requires tracheal transplantation.Studies have confirmed that the capacity of tissue engineering techniques in restoration of extensive tracheal defects in animals and human.Decellularized tracheal matrix has attracted widespread attention for its advantages,such as excellent biocompatibility.Re-epithelialization of the tissue engineered trachea,which remains the major obstacle in tracheal transplantation,plays an important role in protecting the grafts from infection and restenosis.To date,some research focuses on the re-epithelialization of the tissue engineered trachea,but achievements are still far from desired,and further studies are needed to ensure the visibility of the application of tissue engineered trachea.
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Objective: To investigate the effects of superagonistic CD28-specific monoclonal antibody JJ316 (supCD28 MAb) on in vivo proliferation of rat CD4 + CD25+ Fox P3+ Treg(T reg) cells and on allograft rejection reaction in a rat orthotopic tracheal transplantation model. Methods: Rat orthotopic tracheal transplantation models were divided into two groups in the present study. The experimental group was treated with supCD28 MAb(0.5 mg/rat) via intraperitoneal injection on the day of transplantation. Control group was injected with mIgG (0.5 mg/rat). The proportions of CD4+ CD25+ FoxP3+ T cell population in cervical lymph nodes, spleen and peripheral blood monocytes were examined by flow cytometry 5 days after operation. The tracheas were also harvested for histological evaluation. Results: The allografts of the experimental group showed greatly improved airway obliteration, infiltration of inflammatory cells, and respiratory epithelial injury compared with those of the control group. Furthermore, The experimental group had significantly increased CD4+CD25+ FoxP3+ Treg cell population in the lymph nodes, spleen and peripheral blood monocytes compared with those in the supCD28 MAb group ([5.8±1.2]% vs [16.9±4.2]%, [14.8±3.6]%, and [2.9±0.9]%, [3.3±1.3]% vs [2.8±1.4]%, respectively, P<0.05). Conclusion: SupCD28 MAb can attenuate airway inflammation injury after orthotopic tracheal transplantation.
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Objective:To investigate the effects of superagonistic CD28~- specific monoclonal antibody JJ316 (supCD28 MAb) on preferentially expanded rat CD4~+CD25~+Treg (Treg) cells in vivo and its applicability in obliterative airway disease (OAD).Methods:The heterotopic tracheal transplantation model in rats was used.One group received mIgG-treatment(0.5 mg/rat) as control.The experimental group was treated with supCD28 Mab(0.5 mg/rat) via intraperitoneal injection on the day of transplantation.The changes of Treg cell population in cervical lymph nodes were monitored by flow cytometry after 7 days.Tracheas were harvested after 21 days for further histologic evaluation.Results:SupCD28 MAb administration was revealed with a significant increase in the CD4~+CD25~+ T and CD4~+Foxp3~+ T cells population in cervical lymph nodes compared to treatment with mIgG group on day 7 after transplantation,[8.5%±3.4% and 11.5%±2.7% (P<0.05 vs mIgG group)in the supCD28 Mab group,1.8%±1.9% and 3.2%±2.1% in the mIgG group,respectively].Furthermore,the allografts from animals treated with supCD28 MAb were significantly less airway obliteration and destruction of the epithelium compared with that of control group animals on day 21 after transplantation.Conclusion:SupCD28 MAb targets expansion of Treg cells and attenuates airway lumen obliteration in rat obliterative airway disease.
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BACKGROUND: Using the neovascularizing properties of the omentum, we studied the viability and vascularity of the cryopreserved rat tracheal allografts with omental implantation. MATERIAL AND METHOD: The cryopreserved tracheal allografts of eight-week old male Sprague Dawley rats were implanted into the omentum. The rats were divided into the four groups according to the duration of cryopreservation and of omental implantation. We examined the tracheal allografts histologically for viability of cartilages, inflammation and fibrosis of smooth muscle and connective tissue, and degree of vascularity. RESULT: The degree of inflammation in the smooth muscle and the connective tissue of the tracheal allografts was not statistically related to neither the duration of cryopreservation or of omental implantation. The tracheal cartilages of the tracheal allografts were found to be severely calcified in all cases. Significant difference in vascularity was found between the groups I and II (p<0.05). And a sufficient vascularity in the intercartilaginous space was observed in the midportion of the the tracheal allografts as well as both ends. CONCLUSION: In conclusion, the omental implantation for 2 weeks could establish a sufficient vascularity in the intercartilaginous spaces for maintaining the viability of the tracheal allografts. This study might provide a possibility of the sequential tracheal allotransplantation after omental implantation.
Subject(s)
Animals , Humans , Male , Rats , Allografts , Cartilage , Connective Tissue , Cryopreservation , Fibrosis , Inflammation , Muscle, Smooth , Omentum , Rats, Sprague-DawleyABSTRACT
Objective To detect the protective mechanism of trehalose in tracheal cryopreservation.Methods Inbred male Sprague-Dawley (SD) rats were sacrificed with intraperitoneal injection of ketamine(150mg?kg -1).The tracheas were removed and immersed immediately in the freezing medium of low potassium dextran (LPD) solution only(Group Ⅰ) ,containing with 10% dimethylsulfoxide(DMSO)(Group Ⅱ), containing with 0.15mol?L -1 trehalose (Group Ⅲ),and containing with 10% DMSO and 0.15mol?L -1 trehalose (Group Ⅳ) respectively. A sterile plastic tube containing a 1-cm-long trachea was filled with the freezing medium,sealed,and frozen to -80℃ at rate of -1℃ per minute in a programmable freezer.Then the tube was stored in liquid nitrogen(-196℃) for 20 days. Then the specimen was thawed in a 37℃ water bath and rinsed with physiologic saline solution 10 times.Histologic changes before cryopreservation and after thawing were examined in each group. After the specimens were embedded in paraffin,5-(m-thick sections were stained with hematoxylin and eosin.The epithelium and cartilage was assessed. We also observed Bcl-2 and Bax gene expression by immunohistochemistry. At last, some tracheas(SD) after cryopreservation were thawed and transplanted into the abdominal cavity of Wistar rats. The transplanted tracheas were retrieved and assessed histologically.Results Microscopic findings of the tracheas in Group Ⅲ and Group Ⅳ showed their structure were intact and Bax gene expression was lower in cartilage after cryopreservation(20d) compared with other groups,especially in Group Ⅳ.The tracheas in Group Ⅲ and Group Ⅳ grew well after they were transplanted into cavity of Wistar rats heterotopically,too.There were no significant differences among 4 groups in Bcl-2 gene expression.Conclusion In tracheal cryopreservation the trehalose can protect the trachea by protecting the tracheal cartilage.It is one of the protective mechanism that the trehalose inhibit the Bax gene expression of cartilage cells.The concomitant use of trehalose and DMSO has a synergistic effect.