Project description:Background. The lack of noninvasive biomarkers of rejection remains a challenge in the accurate monitoring of deeply buried nerve allografts and precludes optimization of therapeutic intervention. This study aimed to establish the expression profile of circulating microRNAs (miRNAs) during nerve allotransplantation with or without immunosuppression. Methods. Balb/c mice were randomized into 3 experimental groups, that is, (1) untreated isograft (Balb/c M-bM-^FM-^R Balb/c), (2) untreated allograft (C57BL/6 M-bM-^FM-^R Balb/c), and (3) allograft (C57BL/6 M-bM-^FM-^R Balb/c) with FK506 immunosuppression. A 1-cm Balb/c or C57BL/6 donor sciatic nerve graft was transplanted into sciatic nerve gaps created in recipient mice. At 1, 3, 7, 10, and 14 d after nerve transplantation, nerve grafts, whole blood, and sera were obtained for miRNA expression analysis with an miRNA array and subsequent validation with quantitative PCR. Male Balb/c and C57BL/6 mice (age, 10M-bM-^@M-^S12 weeks; weight, 30M-bM-^@M-^S35 g) were purchased from BioLasco (Yi-Lan, Taiwan). The Balb/c mice were randomized into 3 experimental groups: (1) untreated isograft, (2) untreated allograft, and (3) allograft with FK506 treatment. Additional Balb/c and C57BL/6 mice served as sciatic nerve isograft and allograft donors, respectively. These species of mice were selected on the basis of disparity at the MHC locus and prior experience with reciprocal rejection of grafts between these murine strains. FK506 was administered subcutaneously at 1 mg/(kgM-bM-^@M-"d) throughout the experimental course, unless indicated otherwise. At 1, 3, 7, 10, and 14 d after initial surgery (n = 6 animals per group at each time point), sciatic nerve grafts were harvested, and whole blood samples were obtained. Additional sham-operated mice were subjected to the same procedure, including opening of the skin and muscle layers and exposing the sciatic nerve, but without nerve transection or nerve grafting, to measure the effect of FK506 injection on the expression of circulating miRNA. To test the effect of the discontinuation of FK506 treatment on the expression of circulating miRNA, whole blood was drawn at 0, 2, 4, and 6 d after discontinuation of FK506 injection in an additional group of mice with allografts and immunosuppression for 7 d. The whole blood samples (1 mL per mouse) were collected at the indicated times in tubes containing anticoagulant. After the whole blood samples were incubated at room temperature for 15 min, they were centrifuged at 3000 rpm for 10 min, white blood cells were slowly removed from the corresponding layers, and the serum was extracted and stored at M-bM-^@M-^S80M-BM-0C before processing for RNA analyses. All the housing conditions and the surgical procedures, analgesia, and assessments were in accordance with national and institutional guidelines, and an Association for Assessment and Accreditation of Laboratory Animal Care (AAALAC)M-bM-^@M-^Saccredited SPF facility was used. The animal protocols were approved by the Institutional Animal Care and Use Committee (IACUC) of Kaohsiung Chang Gung Memorial Hospital.

Project description:This study aimed to establish the expression profile of circulating microRNAs (miRNAs) during nerve allotransplantation. Experimental design Male Balb/c and C57BL/6 mice (age, 10M-bM-^@M-^S12 weeks; weight, 30M-bM-^@M-^S35 g) were purchased from BioLasco (Yi-Lan, Taiwan). The Balb/c mice served as sciatic nerve allograft donors. The C57BL/6 mice were randomized into the group of nerve allograft transplantation with FK506 treatment and the group without FK506 treatment. These species of mice were selected on the basis of disparity at the MHC locus and prior experience with reciprocal rejection of grafts between these murine strains [18]. The mice were anesthetized by intraperitoneal injection of an anesthetic cocktail consisting of 0.1 mg/g ketamine and 0.01 mg/g xylazine. The anesthetized mice were restrained in a supine position on a heated pad to maintain the body temperature at 37M-BM-0C. Under aseptic conditions, with sterile povidone/iodine preparation and 70% ethanol and sterile instruments and drapes, the skin over the proximal right hindlimb was incised, and the underlying biceps femoris muscle was bluntly dissected to expose the sciatic nerve. An established mouse sciatic nerve allotransplantation model was used. In brief, 1-cm Balb/c donor sciatic nerve grafts were transplanted in reverse orientation into 0.5-cm sciatic nerve gaps created in the recipient Balb/c mice. Tension-free repair was then performed under an operating microscope with three 11M-bM-^@M-^S0 nylon (Ethicon Inc., Somerville, NJ) interrupted epineurial sutures under 40X magnification. The muscle was closed with 5M-bM-^@M-^S0 vicryl sutures, and the skin with interrupted 5M-bM-^@M-^S0 nylon sutures. The animals were monitored to ensure appropriate feeding and diet after surgery. FK506 was administered subcutaneously at 1 mg/(kg-d) throughout the experimental course. At 3, 7, and 14 d after initial surgery (n = 3 animals per group at each time point), the whole blood samples were collected at the indicated times in tubes containing anticoagulant. (F)3d, (F)7d and (F)14d were used to indicate the serum samples of allotransplantation mice with FK506 immunosuppression for 3, 7, and 14 d, respectively. (N)3d, (N)7d and (N)14d were used to indicate the serum samples of allotransplantation mice without FK506 immunosuppression and sacrificed at postoperative 3, 7, and 14 d, respectively. After the whole blood samples were incubated at room temperature for 15 min, they were centrifuged at 3,000 M-CM-^Wg for 10 min, white blood cells were slowly removed from the corresponding layers, and the serum was extracted and stored at M-bM-^@M-^S80M-BM-0C before processing for RNA analyses. Small RNA libraries generated from the serum of mice of above groups were analyzed using an Illumina HiSeq2000 Sequencer.

Project description:Acute allograft rejection is a leading cause for the failure of organ allotransplantation. Identifying the genes involved in the rejection process provides clues to study the mechanisms, and to provide specific gene targets for monitoring, predicting and preventing acute allograft rejection. Using a mice model of skin acute allograft rejection and SAGE method, we analyzed gene expression in the CD4+ T cells of the mice, the cell type known to play critical roles in acute allograft rejection. Our study identifies 402 SAGE tags significantly different from these from the control. From these SAGE tags, we identified 91 increasingly and 85 decreasingly expressed genes, and many genes have not been linked with acute allograft rejection before. Functional classification of these genes shows that apoptosis, transcription regulation, cell growth and maintenance and signal transduction are among the most frequently changed functional groups. Our study provides a genome-wide view for the genes involving acute allograft rejection in the CD4+ T cells, and indicates that acute allograft rejection involves multiple genes in different functional categories. The genes identified from the study provide candidates for further studying the mechanisms and for monitoring, predicting and preventing acute allograft rejection. Female mice of 6-10 week age were used for the study. BALB/c mice (H-2d) and BALB/c severe combined immunodeficient (SCID) mice were from the animal facility of Shandong University (Jinan, China). C57BL/6 (H-2b, B6) were from Vitalriveri Co. ltd (Beijing, China). Mice were maintained in a pathogen-free animal environment during the experimental process. The use of mice for the study was approved by the Institutional Animal Experimental Committee, and animal care and surgical procedures were performed in compliance with the standard animal experimental protocols of Shandong University School of Medicine. The process of generating skin acute allograft rejection followed the established procedure (12). Briefly, dorsal skin of C57BL/6 was transplanted onto the dorsal thorax of BALB/c SCID mice under sterile condition (allotransplant). As a control, dorsal skin of BALB/c mice was transplanted to BALB/c SCID mice (autotransplant). After 28 days of transplantation, CD4+ T cells were harvested from the spleens of BALB/c mice by using the mouse CD4+ T cells enrichment columns (R&D) with the purity >90% as measured by flow cytometry and 8x106 purified CD4+ T cells were adoptively injected into each transplanted mice via the lateral tail vein. The skin graft in each transplanted mice was then monitored daily. The skin graft was considered to fully reject when more than 50% of the skin became necrosis. SAGE Analysis Upon 14 days post CD4+ T cell transferring, CD4+ T cells were collected from the spleens of five mice in each group with adaptive CD4 T cell transferring using the same process described above. Total RNA was extracted from the purified cells by using Trizol reagent (Invitrogen) and mRNA was purified from the total RNA using oligo dT beads (Invitrogen). cDNA was synthesized by using MMLV reverse transcriptase and oligo(dT) primers (MBI-add full name). SAGE libraries from 4 allotransplant and autotransplant groups were constructed following the standard procedure (13). For each SAGE library, 1,200 sequences were collected through an ABI 3730 DNA sequencer (Applied BioSystems). SAGE tags were extracted from the sequences by using the SAGE2000 software (Invitrogen).

Project description:Purpose: We compared the levels of miRNA specific for DEGs in isograft corneas with those in normal corneas, as well as the levels of miRNA specific for DEGs in allograft corneas with those in isograft corneas, to gain a better understanding of molecular variables that affect corneal graft rejection pathways. Methods: Illumina Hiseq 2500 deep sequencing was used to screen for differentially expressed genes (DEGs) in matched pairs of isograft corneas and normal corneas, allograft corneas and isograft corneas. Potential target genes among the DEGs were predicted using target prediction software (TargetScan, Miranda, miRDB, and CLIP), and the overlay portion was analyzed using the Gene Ontology (GO) database and the Kyoto Encyclopedia of Genes and Genomes (KEGG). An analysis of the interactions between DEG proteins (PPI analysis) and a MetaCore software analysis. Results: Our results showed that 22 miRNAs were significantly upregulated and 4 were significantly downregulated in the isograft group when compared with the control group (P < 0.01), while 17 miRNAs were significantly upregulated and 3 were significantly downregulated in the allograft group when compared with the isograft group (P < 0.01). Among the miRNAs with altered expression levels, miR-155-5p, miR-142-3p, miR-142-5p, and miR-223-3p displayed simultaneous changes in the above two comparisons. Potential target genes among the DEGs were predicted using target prediction software, and the overlay portion was analyzed using the Gene Ontology (GO) database and the Kyoto Encyclopedia of Genes and Genomes (KEGG). GO and KEGG analyses showed that the DEGs were mainly involved in metabolic pathways, cytokine secretion, and tumor immunity functions. An analysis of the interactions between DEG proteins (PPI analysis) and a MetaCore software analysis of 4 key DEGs revealed that the genes regulated by miR-155-5p played important roles in the miRNA-mRNA regulatory network. Furthermore, the MetaCore analysis identified C/EBP beta, p53, and sp1 as key transcription factors in that network. Conclusions: Our study identified transplanted corneas-specific miRNA in matched pairs of isograft corneas and normal corneas, allograft corneas and isograft corneas. Furthermore, bioinformatics analysis of the key miRNA regulatory network revealed the molecular mechanisms, which suggests miRNAs may as new molecular targets for treating corneal injuries and corneal transplant rejection

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Profiling circulating microRNA expression in a mouse model of nerve allotransplantation (part 2)

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