Fracture healing in osteoporotic mice
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE51686 | GEO | 2013/10/25
SECONDARY ACCESSION(S): PRJNA224559
REPOSITORIES: GEO
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Project description:Genome-wide comparative gene expression analysis of callus tissue of osteoporotic mice (Col1a1-Krm2 and Lrp5-/-) and wild-type were performed to identify candidate genes that might be responsible for the impaired fracture healing observed in Col1a1-Krm2 and Lrp5-/- mice. To investigate bone healing in osteoporosis, we performed fracture healing studies in wild-type mice (C57BL/6 genetic background) and the low bone mass strains Col1a1-Krm2 and Lrp5-/- (Schulze et al., 2010; Kato et al., 2002). Osteotomy was set in femora of female mice and stabilized by a semi-rigid fixator to allow fast bone healing (RM-CM-6ntgen et al., 2010). 21 days post surgery we analyzed the fracture calli by biochemical/histological methods, as well as micro-computed tomography, and observed impaired fracture healing in Col1a1-Krm2 and Lrp5-/- mice in comparison to wild-type. To identify genes that may be responsible for the impaired healing in osteoporotic mice, we performed microarray analysis of three independent callus samples of each genotype. The callus tissue was taken 10 days after surgery, because extensive bone formation took place at this point.
2013-10-25 | E-GEOD-51686 | biostudies-arrayexpress
Project description:Bone fractures, the most common musculoskeletal injuries, heal through three main phases: inflammatory, repair, and remodeling. Around 10% of fracture patients suffer from impaired healing that requires surgical intervention, a huge burden on the healthcare system. The rate of impaired healing increases with metabolic diseases such as obesity-associated hyperglycemia/type 2 diabetes (T2D), an increasing concern given the growing incidence of obesity/T2D. Immune cells play pivotal roles in fracture healing, and obesity/T2D is associated with defective immune-cell functions. However, there is a gap in knowledge regarding the stoichiometry of immune cells that populate the callus and how that population changes during different phases of healing. Here, we used complementary global and single-cell techniques to characterize the repertoire of immune cells in the fracture callus and to identify populations specifically enriched in the fracture callus relative to the unfractured bone or bone marrow. Our analyses identified two clear waves of immune-cell infiltration into the callus: the first wave occurs during the early inflammatory phase of fracture healing, while the second takes place during the late repair/early remodeling phase. Innate immune cells were activated during the early inflammatory phase, but in later phases they returned to homeostatic numbers and activation levels. Of the innate immune cells, distinct subsets of activated dendritic cells were particularly enriched in the inflammatory healing hematoma. In contrast to innate cells, lymphocytes, including B and T cells, were enriched and activated in the callus primarily during the late repair phase. The Diet-Induced Obesity (DIO) mouse, an established model of obesity-associated hyperglycemia and insulin resistance, suffers from multiple healing defects. Our data demonstrate that DIO mice exhibit dysregulated innate immune responses during the inflammatory phase, and defects in all lymphocyte compartments during the late repair phase. Taken together, our data characterize, for the first time, immune populations that are enriched/activated in the callus during two distinct phases of fracture healing and identify defects in the healing-associated immune response in DIO mice, which will facilitate future development of immunomodulatory therapeutics for impaired fracture healing.
2023-09-01 | GSE240390 | GEO
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.
2007-11-03 | E-GEOD-1371 | biostudies-arrayexpress
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
2004-10-06 | GSE1371 | GEO
Project description:Traumatic brain injury (TBI) accelerates fracture healing, but the underlying mechanism remains largely unknown. Accumulating evidence indicates that the central nervous system plays a pivotal role in regulating immune system and skeleton, however, the impact of TBI on hematopoiesis commitment was overlooked. Here, we found that the dramatically elevated sympathetic tone accompanied with TBI-accelerated fracture healing; chemical sympathectomy blocks TBI-induced fracture healing. Importantly, the adrenergic hypersensitivity swiftly skews bone marrow hematopoietic lineage cells toward anti-inflammation myeloid cells within 14 days, which favor fracture healing. Knockout of β3- or β2-adrenergic receptors (ARs) eliminate TBI mediated anti-inflammation macrophage expansion and TBI-accelerated fracture healing. Moreover, β3- and β2-ARs agonists synergistically promote M2 macrophages infiltration in callus and accelerate bone healing process. Our results suggest that TBI shapes the anti-inflammation environment during early stage of fracture healing, implicating the sympathetic nerve system as a potential target that can be exploited to treat fracture.
2023-04-12 | GSE229258 | GEO
Project description:alpha-CGRP is a neuropeptide that is also expressed in the fracture callus during bone regeneration. Our aim was to evaluate the role of alpha-CGRP in the context of fracture healing. Therefore we investigated the effect of alpha-CGRP deficiency on fracture callus formation. We used microarray analysis to compare the global gene expression of fracture calli from alpha-CGRP deficient mice and WT mice.
2020-09-02 | GSE148720 | GEO
Project description:Fracture healing is a process that involves many cell populations. In this study we characterized gene expression in a subset of cells involved in fracture healing. αSMACreERT2 mice crossed with Ai9 reporter mice that express tdTomato fluorescent protein after Cre-mediated activation were used as an experimental model. αSMA-expressing cells were labeled by tamoxifen administration, then periosteal cells from the tibia were isolated two days later (controls), or tibial fractures were performed and periosteum/soft callus tissue was collected after 2 and 6 days. The tdTomato positive cell population was isolated by flow cytometry, and subjected to microarray analysis. Histology and cell surface marker analysis indicates that αSMACreERT2 labels a mainly mesenchymal population in the periosteum that expands after fracture, and contributes to both osteogenic and chondrogenic elements of the fracture callus. We were therefore able to examine gene expression in a defined population during the early stages of fracture healing. Total RNA was obtained from the tomato positive cells within the periosteal compartment of fractures from αSMACreERT2/Ai9 mice. Control animals were given 2 doses of tamoxifen, and periosteum was collected and labeled cells sorted (8-9 sex-matched mice per group). Fractures were performed after the second dose of tamoxifen, and tomato positive cells from periosteum/callus tissue were isolated 2 and 6 days after fracture (4-8 animals per sample pooled). 3 replicates for each sample are included.
2013-11-27 | E-GEOD-45156 | biostudies-arrayexpress
Project description:Maturation of the 3¢ end of almost all eukaryotic messenger RNAs (mRNAs) requires cleavage and polyadenylation. Most mammalian mRNAs are polyadenylated at different sites within the last exon, generating alternative polyadenylation (APA) isoforms that have the same coding region but distinct 3¢ untranslated regions (UTRs). The 3¢UTR contains motifs that regulate mRNA metabolism; thus, changing the 3¢UTR length via APA can significantly impact gene expression. Endochondral ossification is a central process in bone healing, and the impact of APA on gene expression during this process is unknown. Here, we report widespread utilization of APA that impacts multiple pathways with established roles in bone healing. Importantly, progression of endochondral ossification is typified by global 3¢UTR shortening that is coupled with an increased abundance of shortened transcripts as compared to all other transcripts, underscoring the role of APA in promoting gene expression during endochondral bone formation. Our mechanistic studies of genes that undergo APA in the fracture callus uncover an intricate regulatory network in which APA boosts the expression of collagen, type I, alpha 1 (Col1a1) and Col1a2 genes, which encode the 2 subunits of the abundantly expressed protein collagen 1. APA does so via shortening the 3¢UTRs of Col1a1 and Col1a2 mRNAs, which removes the binding sites of miR-29a-3p that otherwise potently triggered the degradation of both transcripts. Taken together, our study takes the lead in characterizing crucial roles of APA in tailoring the 3¢UTR landscape and regulating gene expression during fracture healing.
2023-01-11 | GSE205053 | GEO
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.
2007-11-03 | E-GEOD-1685 | biostudies-arrayexpress
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.
2009-09-01 | E-GEOD-17825 | biostudies-arrayexpress