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:TLR4/NF-ÎºB signaling plays a central mediator in response to danger signals released in the muscle ischemia-reperfusion injury (IRI). This study was designed to profile TLR4/NF-ÎºB-responsive microRNAs (miRNAs) in the skeletal muscles following IRI. Following 2 h of ischemia and subsequent reperfusion for indicated times (0 h, 4 h, 1 d, and 7 d) of the isolated thigh skeletal muscles based on femoral artery perfusion of C57BL/6, Tlr4â/â, and NF-ÎºBâ/âmice, the muscle specimens were analyzed with an miRNA array to detect the TLR4/NF-ÎºB-responsive miRNAs. Male C57BL/6 mice (10â12 weeks of age, 22â35 g) were purchased from BioLasco (Taiwan). Tlr4â/â (C57BL/10ScNJ) and NF-ÎºBâ/â (B6.Cg-Nfkb1tm1Bal/J) mice were purchased from Jackson Laboratory (Bar Harbor, ME, USA). All housing conditions were established and surgical procedures, analgesia, and assessments were performed in an AAALAC-accredited, SPF facility following national and institutional guidelines. Animal protocols were approved by the IACUC of Chang Gung Memorial Hospital. Mice were anesthetized with an anesthetic cocktail consisting of 0.1 mg/g ketamine and 0.01 mg/g xylazine, given as an intraperitoneal injection (0.01 ml/g body weight). After the induction of anesthesia, the mice were restrained in a supine position on a heating pad to maintain body temperature at 37Â°C. The quadriceps muscle perfused based on the femoral artery of the mouse was carefully isolated away from the femoral bone and the underlying adductor muscle group. In the ischemic group, ischemia was induced by placing a microvascular clamp carefully across the proximal site of vascular pedicle for 2 h and then the microvascular clamp was removed. Good vascular inflow and outflow through the pedicle was verified under direct magnified vision. In the sham-operated control group, the muscle was isolated without microvascular clamp being applied. The incision wound was closed with interrupted sutures (4-0 nylon) and the animals were allowed to awaken in the remaining periods of reperfusion. The harvested muscles were frozen in isopentane chilled in liquid nitrogen and stored at -80Â°C. For the miRNA array experiments, the isolated skeletal muscles of C57BL/6 mice after 2 h of ischemia and 0 h, 4 h, 1 d, and 7 d of reperfusion as well as of Tlr4â/âand NF-ÎºBâ/â mice after 2 h of ischemia and 1 d of reperfusion were used in 3 replicate experiments.

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Circulating microRNA Signatures in Mice Exposed to Lipoteichoic acid

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