Objective To analyze the composition and function of residual cells in pre-transplantation human thymic slices by single-cell transcriptomics sequencing(scRNA-seq),and established a quality assessment method for thymic slices based on the expression levels of molecular markers in the culture supernatant.Methods The discarded thymus from 18 patients with congenital heart disease undergoing surgical treatment in Department of Cardiothoracic Surgery of Children's Hospital Affiliated to Chongqing Medical University from May 2023 to January 2024 were collected and prepared into thymic slices.After the slices were cultured in vitro for 14 d,scRNA-seq was employed to identify the residual cell types,and gene ontology(GO)and Kyoto encyclopedia of genes and genomes(KEGG)enrichment analysis was performed to analyze the biological function of the residual cells.Then based on the literature concerning thymic slice culture,the molecular markers indicating thymocyte function were screened out.ELISA was applied to detect the changes in protein levels of molecular markers in the supernatant.Receiver operating characteristic(ROC)curve was plotted and assess the value of the molecular markers in the supernatant in evaluating the quality of thymic slices with area under the curve(AUC).Then,the qualified and unqualified thymic slices determined by our obtained molecular markers were transplanted subcutaneously into male nude mice(6～8 weeks old,weighing 14～17 g),respectively,and the male nude mice without transplantation of the thymic slices served as control group.Flow cytometry and histologic analysis were utilized to observe the immune reconstitution after transplantation.Results ① scRNA-seq identified 11 cell types in thymic slices,dominated with epithelial cells,fibroblasts,and T cells.GO and KEGG enrichment analysis showed that epithelial cells were involved in enrichment entries related to chemotaxis,epithelial cell development,cell matrix adhesion and tight junction;fibroblasts were involved in enrichment entries related to extracellular matrix,epithelial cell proliferation,negative regulation of cell migration,and regulation of actin cytoskeleton;T cells were mainly related to T cell differentiation,regulation of T cell activation,T cell apoptosis,and T cell receptor signaling.② Molecular markers,CCL19,CCL21,CXCL12,CXCL16,IL16 and SELL were identified to indicate thymocyte function.Compared with the levels of the first day,the protein secretions of CCL19,CCL21,CXCL12 and CXCL16 were significantly increased during in vitro culture(P<0.05),while the protein secretions of IL16 and L-selectin(protein form of SELL)were significantly decreased(P<0.05).The combined predictor Pre1 from subset of cytokines(IL16 and L-selectin)had the highest value in the quality assessment of thymic slices after 1 d of culture(AUC=0.883),and the combined predictor Pre2 from subset of cytokines(CCL19,CCL21,CXCL12 and CXCL16)had the highest value in the quality assessment after 14 d of culture(AUC=0.948).③ Transplantation in nude mice indicated that the qualified thymic slices could develop to thymus structure in vivo,and effectively increase the proportion of T cells in peripheral blood(P<0.01),while the unqualified thymic slices could not obtain the reconstitution of T cell development.Conclusion The main residual component cells in thymic slices are epithelial cells,fibroblasts and T cells.IL16 and L-selectin can be used as potential indicators to determine the quality of donor thymic samples.CCL19,CCL21,CXCL12 and CXCL16 can effectively evaluate the quality of thymic slices before transplantation.

This study was designed to explore the immune reconstitution efficacy of human thymic slices transplanted into renal capsule,subcutaneous or muscle of nude mice,and further explore the optimal location of heterotopic transplantation.The thymus tissue discarded from congenital heart disease patients was made into 0.5-1 mm thick tissue sections and cultured in vitro to remove immune cells.H&E staining and immunohistochemical staining were used to assess the residual tissue structure and cell types in thymic slices,while quantitative PCR methods were used to assess the function of residual cells in thymic slices.Then thymic slices were transplanted into the renal capsule,subcutaneous or muscle of nude mice,and the immune reconstitution efficacy was compared by flow cytometry and histology.Data showed that after 14 days of culture in vitro,the clearance rate of T lymphocytes in the thymic slices was more than 90%,and the epithelial cell network structure of the tissue was intact,while a large number of macrophages,dendritic cells and endothelial cells remained.Quantitative PCR results showed that the gene expression levels of epithelial cell markers and secreted cytokines in cultured thymic slices could be effectively maintained.Flow cytometry showed that at 16 weeks after transplantation,the proportion of T cells in peripheral blood of mice in different transplantation groups were significantly increased,whereas the proportion of T cells in muscle group was the highest.In situ histological examination showed that the regeneration of thymus tissue was detected at all three transplant sites.In addition,the graft detection rate was 40%in the renal capsule group,60%in the subcutaneous group and 100%in the musclegroup.In conclusion,the human thymic slices cultured in vitro for 14 days retain a complete thymic matrix microenvironment.Transplantation of human thymic slices can effectively reconstruct the ratio of T cells in nude mice,and the muscle is the most effective transplantation site.

This study was aimed to examine the effectiveness of a gene transfer of human TGFbeta1 gene into endothelial cells and to determine whether TGFbeta1 increases ECM expression of endothelial cells. With the help of DOTAP, endothelial cells were transfected with pMAMneoTGFbeta1. The positive cell clones were selected with G418. The stable transfection and expression of TGFbeta1 in the endothelial cells were determined by immunofluorescence analysis. The expression levels of collagen I and fibronectin in the transfected and untransfected endothelial cells were determined by Western blot. The adhesion force between endothelial cells and matrix was determined by a micropipette technical system. The results showed abundant TGFbeta1 stable expression in the endothelial cells. TGFbeta1 gene was noted to increase collagen I and fibronectin expression and increase the adhesion between endothelial cells and matrix. These findings indicated that TGFbeta1 can be used in vascular tissue engineering for the enhancement of endothelial cells adhesion.
Cell Adhesion ; Cells, Cultured ; Collagen Type I ; biosynthesis ; genetics ; Endothelium, Vascular ; cytology ; physiology ; Extracellular Matrix ; metabolism ; physiology ; Fibronectins ; biosynthesis ; genetics ; Humans ; Tissue Engineering ; Transforming Growth Factor beta ; biosynthesis ; genetics ; Umbilical Veins ; cytology

To explore the human smooth muscle cells seeding in blood vessel of minor pig after trypsin treatment and provide data for xenotransplantation and for using pig vessel in tissue engineering. HE and silver stain were used for checking the smooth muscle cells seeding in acellular blood vessel. The results showed that the smooth muscle cells seeding succeeded and the smooth muscle cells were in normal morphological distribution. These demonstrate that the pig aorta can be used for smooth muscle cells seeding, and hence for constructing new vascular grafts.
Animals ; Bioprosthesis ; Blood Vessel Prosthesis ; Blood Vessels ; cytology ; Cell Separation ; Cell Transplantation ; Female ; Humans ; Male ; Muscle, Smooth, Vascular ; cytology ; Swine ; Swine, Miniature ; Tissue Engineering ; methods ; Transplantation, Heterologous

BACKGROUND: Changes of elastic fibers in middle cerebral artery(MCA)is close related withthe aged cerebrovascular disease.OBJECTIVE: To observe the changes of elastic fibers of MCA in different aging rats.DESIGN: A descriptive and controlled study based on experimental animals.SETTING: Department of anatomy and central laboratory in a university.MATERIALS: Totally 36 healthy Wistar rats with either gender, weighing 200 - 280 g, were selected from the Animal Institute of the third medical military university of Chongqing[certification SCXX (army) 2002-007].INTERVENTIONS: Changes of elastic fibers of MCA of different aging rats were observed with light microscope, transmission electron microscope and image analysis system. MAIN OUTCOME MEASURES: ①) Major outcome: changes of elastic lamella in MCA of different aging rats; ②) Secondary outcome: ultramicrostructural changes of internal lamella under the transmission electron microscope. RESULTS: With the increase of age, the folded extent and quantity of internal elastic lamella were decreased, and the content of elastic fibers were also decreased significantly( P ＜ 0.01 ). However, the ratio of collagen fibers to elastic fibers was increased significantly( P ＜ 0.01 ) . In the aging group above 24 months, the internal elastic lamina thinned, delaminated and disrupted, and the lipid deposited in it. Endothelial cells and smooth muscle cells passed through the internal elastic lamina. CONCLUSION: Changes of elastic fibers may be related with the increased susceptibility to the cerebrovascular disease in aged people.

This study sought to explore the change of the major histocompatibility complex (MHC) antigen expression and the endothelization of blood vessel in minor pig after trypsin treatment, and to provide data for xenotransplantation and pig vessel for use in tissue engineering. Western blot assays were conducted for detecting the expression of MHC xenoantigens. Scanning electron microscopy was used for checking the endothelization of decellularized blood vessel. The results showed that MHC antigen is not expressed after trypsin treatment. The endothelization is accomplished. The endothelial cells have normal morphological distribution. These demonstrate that the antigen of pig aorta is significantly decreased and it can be used for constructing new vascular grafts.
Animals ; Bioprosthesis ; Blood Vessel Prosthesis ; Cells, Cultured ; Endothelial Cells ; cytology ; Female ; Major Histocompatibility Complex ; physiology ; Male ; Swine ; Swine, Miniature ; Tissue Engineering ; methods ; Tissue Scaffolds

This study was conducted to examine the effectiveness of a gene transfer of human TGF beta 1 gene into smooth muscle cells and whether the TGF beta 1 can increase elastin expression of smooth muscle cells. With the help of DOTAP, smooth muscle cells were transfected with pMAMneoTGF beta 1. The positive cell clones were selected with G418. The stable transfection and expression of TGF beta 1 in the smooth muscle cells were determined by immunofluorescence analysis. The expression of elastin in the transfected and untransfected cells were determined by in situ hybridization. The adhesion force between smooth muscle cells and matrix was detected by micropipette system. The results showed abundant TGF beta 1 stable expression in smooth muscle cells. TGF beta 1 gene can increase two-three times elastin expression and increase the adhesion between smooth muscle cells and matrix. TGF beta 1 can be used in vascular tissue engineering to increase smooth muscle cells adhesion.
Cell Adhesion ; Cells, Cultured ; Elastin ; biosynthesis ; Humans ; In Situ Hybridization ; Muscle, Smooth, Vascular ; cytology ; metabolism ; Transfection ; Transforming Growth Factor beta ; biosynthesis ; genetics ; physiology ; Transforming Growth Factor beta1

Objective To investigate the effects of zinc finger protein gene A20 on the inhibition of lipopolysaccharide (LPS) induced interleukin 8 (IL 8) expression in endothelial cells. Methods Plasmid pcDNA3.1EHA20 was transfected into human umbilical vein endothelial cells (HUVECs) by DOTAP method. The positive cell clones were screened with G418. The stable transfection and expression of A20 in HUVECs were determined by immunofluorescent analysis. IL 8 expression was detected by sandwich ELISA with double monoclonal antibodies. Results High expression of A20 gene in HUVECs transfected with pCDNA3.1EHA20 was confirmed by immunofluorescent analysis. IL 8 expression increased in LPS induced endothelial cells. A20 gene could inhibit more than 70% LPS induced IL 8 expression ( P

To explore the changes of the antigen expression and the biomechanical characteristics of blood vessel in Banna little ear pig before and after trypsin treatment, and provide data for xenotransplantation and pig vessel using for tissue engineering. Geometric morphology and microstructure of pig cartoid artery were stuided quantitatively by histologic method and computer image analysis. The relationship between pressure and diameter was observed at different period of time before and after trypsin treatment. Affinity-immunohistochemistry assay was conducted to detect the expression of xenoantigens (alpha-Gal). The results showed that alpha-Gal antigen is only expressed in vascular endothelial cellsouly. There is no significant difference in blood vessel compliance. These demonstrate that the antigenicity of pig carotid artery is significantly reduced, however, the mechanical characteristics did not change significantly. We suppose that pig vessels treated by trypsin can be used as the substrate material for vascular tissue engineering.
Animals ; Animals, Inbred Strains ; Antigens, Heterophile ; biosynthesis ; Blood Vessels ; drug effects ; physiology ; Female ; Male ; Stress, Mechanical ; Swine ; Tissue Engineering ; Trypsin ; pharmacology

Objective To isolate the bone marrow mesenchymal stem cells(MSCs) from the GFP-expressing mouse, and to study the osteoblastic differentation of the cells. Methods MSCs were isolated by density gradient centrifugation, then the clutrued cells were induced to osteoblastic differentiation using the conditional medium. We detectd the expression of GFP and MSCs differentiation into osteoblasts by histochemistry and immunochemistry. Results The MSCs maintained the expression of GFP during expanded and induced process. After induced for 10 days, lots of alkaline phosphatase and osteoclcin staining positive cells were observed.Conclusion The MSCs of GFP-expressing mouse were successfully isolated and differentiated into ostoblasts. It may be valuable for tracing the seeding cells in tissue engineering bone.