Project description:Time-point expression analysis of fractures calluses at 1, 3, and 5 days post-fracture in young and old BALB/c mice. Femur fractures were generated on female c57BI6 mice in triplicate: 8 month old retired breeders (old mice) and 6 week old mice (young mice) were used. 1, 3, and 5 days post-fracture, fracture calluses were dissected and total RNA isolated. Expression profiling was performed using Affymetrix's Mouse Genome 430 2.0 array.
Project description:10% of the fifteen million bone fractures each year that occur in the US fail to heal, which leads to significant loss of function, morbidity, and mortality. However, very little is known about the cellular and molecular mechanisms underpinning inferior healing. Two perturbed fracture models, surgically induced ischemia and the genetic deletion of the self-antigen CD47, were studied to identify unifying cellular and molecular mechanisms. C57Bl/6 wild-type (WT) mice with intact vasculature (WT Intact), WT mice with induced ischemia (WT Ischemic), and CD47-null mice with intact vasculature (CD47-KO) underwent transverse tibial fractures. Single-cell RNA-sequencing (scRNAseq) was performed during the inflammatory stage (4 days post-fracture) and the stromal stage (7 days post fracture) to assess transcriptomic alterations in perturbed fracture calluses.
Project description:mRNA gene expression was measured in intact female Sprague-Dawley rats at 6 (young), 26 (adult) and 52 (older) weeks of age at the time of fracture. Samples were collected at 0, 0.4, 1, 2, 4, and 6 weeks after fracture. RNA from two rats were pooled for each Affymetrix Rat U34A array. Mid-shaft, simple, transverse left femoral fractures were induced after retrograde intramedullary rod fixation with a Bonnarens and Einhorn device. Samples were collected from one third of the femoral length, centered on the fracture site, including the external callus, cortical bone, and marrow elements. Keywords = rat Keywords = fracture Keywords = age Keywords = time Keywords = femur Keywords: other
Project description:We used microarrays to detail the global programme of gene expression underlying cellularisation and identified distinct classes of up-regulated genes during this process. Geriatric fractures take longer to heal and heal with more complications than those of younger patients; however, the mechanistic basis for this difference in healing is not well understood. To improve this understanding, we investigated cell and molecular differences in fracture healing between 5 month-old (young adult) and 25 month-old (geriatric) mice healing utilizing high-throughput analysis of gene expression.
Project description:This is a study of femoral fracture healing in female rats 16 weeks old at fracture to compare intramedullary nailing, screw and plate fixation, and sham surgery. The sham surgery group received a surgical exposure of the femur, but no fracture, no plate, and no nail. Samples were collected at 1 day, 3 days, 1 week, 2 weeks, 4 weeks, and 6 weeks after surgery. Each sample is a pool of RNA from three rats from the same surgery group at the same time point after fracture. The middle third of the femur was collected with the cortical bone, fracture callus, and marrow elements. Mid-diaphyseal, simple, transverse fractures were induced by a Gigli saw. The no fracture sample was a time 0 control collected on the day of surgery from intact rats. Keywords = rat Keywords = fracture Keywords = plate Keywords = nail Keywords = time Keywords = femur Keywords: time-course
Project description:This is a study of femoral fracture healing in female rats 16 weeks old at fracture to compare intramedullary nailing, screw and plate fixation, and sham surgery. The sham surgery group received a surgical exposure of the femur, but no fracture, no plate, and no nail. Samples were collected at 1 day, 3 days, 1 week, 2 weeks, 4 weeks, and 6 weeks after surgery. Each sample is a pool of RNA from three rats from the same surgery group at the same time point after fracture. The middle third of the femur was collected with the cortical bone, fracture callus, and marrow elements. Mid-diaphyseal, simple, transverse fractures were induced by a Gigli saw. The no fracture sample was a time 0 control collected on the day of surgery from intact rats.
Project description:mRNA gene expression was measured in intact female Sprague-Dawley rats at 6 (young), 26 (adult) and 52 (older) weeks of age at the time of fracture. Samples were collected at 0, 0.4, 1, 2, 4, and 6 weeks after fracture. RNA from two rats were pooled for each Affymetrix Rat U34A array. Mid-shaft, simple, transverse left femoral fractures were induced after retrograde intramedullary rod fixation with a Bonnarens and Einhorn device. Samples were collected from one third of the femoral length, centered on the fracture site, including the external callus, cortical bone, and marrow elements. Keywords = rat Keywords = fracture Keywords = age Keywords = time Keywords = femur Keywords: other
Project description:Study of rat femur fracture healing in young (6 weeks old), adult (26 weeks old), and older (52 weeks old) rats with samples collected at 0 time (no fracture) and at 0.4, 1, 2, 4, and 6 weeks after fracture. RNA from two rats were pooled for each array. Keywords = rat, femur, fracture, age, time Keywords: time-course
Project description:A study of rat femoral fracture healing in young (6 weeks old at fracture), adult (26 weeks old at fracture), and old (52 weeks old at fracture) rats. Samples were collected at time of surgery (intact controls) and at 3 days, 1 week, 2 weeks, 4 weeks, and 6 weeks after fracture. Samples were the mid third of the femoral length including the external callus, cortical bone and marrow elements. Fracture was stabilized with an intramedullary rod prior to fracture with a Bonnarens and Einhorn device. Keywords: time-course
Project description:Despite its regenerative capacity, the healing potential of bone tissue declines with aging. With the increase in global aging population, bone fractures pose a tremendous burden to the healthcare system. Therapeutic interventions that circumvent age-associated impairments and promote bone tissue regeneration are attractive options for geriatric fracture repair. We and others have demonstrated the role of extracellular adenosine in bone homeostasis and regeneration. Herein, we examined the changes in extracellular adenosine with aging and the potential of local delivery of adenosine to promote fracture healing using aged mice as a model system. Extracellular adenosine level was significantly lower in aged bone tissue compared to those from young mice. Concomitantly, the ecto-5′-nucleotidase CD73 expression was also found to be lower in the aged bone tissue. Local delivery of adenosine using injectable, in situ curing microgel delivery units yielded a pro-regenerative environment and promoted fracture healing in aged mice. This study offers new insights into age-related physiological changes in adenosine levels and demonstrates the therapeutic potential of adenosine supplementation to circumvent the compromised healing of geriatric fractures.